DODGE CARAVAN ENGINE BELT

I presume you have a service manual, though I may include brief pointers from it to make this advice more cohesive.

BELT COMING OFF
Some owners have had difficulty with the engine accessory drive belt popping off in heavy rain or snow, with the Chrysler 3.3/3.8 litre engine. The one vehicle I examined after it happened again showed noticeable but not severe uneveness of wear across the belt, whereas my vehicle does not and has never had the belt come off.

The Gates belt Technical Handbook has information on checking pulley alignment to prevent that. (The handbook is described in the belt catalogue. Gates' web site has a Timing Belt Replacement Manual with CD - replacement tips and belt p/ns, expect a U$35. price tag. Gates' web site also shows a laser alignment tool (p/n 91006 c/w glasses) that sits on one pulley and points at another. Refer to the Gates tool brochure for the laser and tensioner tools.
And it promotes tensioner designs to avoid binding. (I've been suspicious of mine, when the installed belt was slightly long and had less surface area due to cross-grooves (perhaps designed to reduce effect of water), and when it stuck partly retracted while reinstalling the belt. On removal to replace the alternator I purchased a new one, finding the old one to not fully extend (position of the mechanism relative to notch in housing, and the pointer).)

One recommendation to avoid belt coming off is to ensure there is a splash shield below the lowest pulley.

REMOVING/RE-INSTALLING THE BELT
You'll want a good tensioner tool for changing the belt - access is very tight and you need a long lever to apply torque to relieve tension.

A bent tool is best so the transmission computer does not limit rotation but you get a good lever arm. Some tool kits sold for such work have a short bar extender that can be assembled at an angle to their longer bar, so it fits under the computer which projects from the firewall, with the long bar coming off it at an angle, to give more travel while still providing length for leverage. But most of those kit would need a 1/2" drive socket at the tensioner, which would be too long to fit between the tensioner nut and structure, especially with the badly placed clamp for a brake line reducing clearance! The Lisle brand tool kit may be more versatile. Great Neck Saw Mfg. Inc. (aka 'OEM Tools') kit 24687 has what appears to be two segments to the long bar, fixable at angle you need (you can then ignore the stupid short extension with 1/2" drive), I'll be trying that when I put a new belt on. Kits sould have extra-short sockets, useful on the Caravan with 3.3L engine (a typical flat-bar tool may fit with a regular 3/8" drive socket, depending in part on where the brake line clamp is on the frame, it's desirable to use a 12-point socket to maximize rotation within limits the tool can travel, whereas the cheap kit's shallow socket is 6 point. Note there are fancy kits with some kind of ratcheting design, but they look as though they will not fit this vehicle ad the nut on the idler is recessed thus you need a socket sticking into it.
And note that travel is limited by granularity of the socket, even 12-point, limiting initial angle.
OR you may be able to use a ratcheting box end wrench that has a bit of offset, and a pieced of pipe to extend handle for leverage. Tricky to keep wrench on idler bolt head, perhaps jam piece of wood between it and frame (I suggest wood against the wrench and perhaps foam against frame.

You can disconnect the fuel lines to the fuel rails at the body ends, using your fingers and an open end wrench - look in the General section of 14 of the SM. Note instruction to lubricate fittings with engine oil on reassembly.

PROBLEM ON MY 93 is that brake line and clamp prevent even short 15mm socket on bar from going into place to engage idler. So removal of it (3/8" screw head - brakes on this beast are SAE not metric) and somehow drilling a hole to relocate will be necessary. I bent the line away enough to get at the idler, using very long plies from above, probably could just pull it down from below.
And the fuel lines from body to fuel rails get in the way of proper movement of the bar tool. You can disconnect the, using a 10mm open end wrench to push the ridge on bottom of joint against the large part that you push down on just to hold it against your upward push with wrench. Remember to put a bit of engine oil on them disconnects when reconnecting.
Even then you want a segmented bar with two pieces angled to each other, because of the granularity of a 12-point socket, but see above re availability.

A non-ratchet 3/8 driver bar with tube slipped over it and a short 15 mm socket may work. I am leaning toward either an open end wrench or a closed-end wrench with integral ratchet, with a tube slipped over the end (perhaps either short and slideable or long and bent to clear the computer), noting that a 15/13mm wrench would have a somewhat narrow end.

(You'll need the diagram from the service manual (memorize it, and of course recognize that ribs go against ribs, the back side of the belt against smooth pulleys), a stretchy sky hook would help - a string of elastic bands to take the weight of the belt to keep it up while wrapping it around each pulley.

Beware you'll probably have to go under the vehicle to get the belt around the lower pulleys, which for the Caravan beast means jacks (you don't want ramps because that means you have to have a plaftform to stand on while working up top).

I no longer recommended hanging the top end of the belt up immediately after slipping off of the alternator pulley if that's what you are servicing, because the hanger and belt are inconvenient when removing bolts for the big bracket, might as well get it out of the way and do the bother of re-threading later.

I recommend starting by hanging the belt on the tensioner pulley, then get it around everything else but laying above the idler.
Then you can pull on the tensioner tool with one hand and with your other hand get the belt under the idler pulley. If tight, you can put something against the transmission computer/firewall to hold the tool forward, to have both hands on the belt.
(The driven pulleys have a lip on their edge and grooves, which makes it far more difficult to install a tight belt, and the newer plastic tensioner pulley does not have the generously rounded edge of the metal idler pulley which is easier to force the belt onto the metal idler pulley with less chance of damaging it. (Perhaps that helps prevent coming off from slush/snow.)