Glad to hear you survived, I bet it was a very scarey experience! Just take things slow.
I still have my van also, it is in storage for my spring break. I have to replace the front end soon, cannot even drive the thing without ending up in the other lane.
Anyways, for the differential I am assuming you are just changing out the fluid. Well the first thing to do is layout the tools and parts.
Tools: Wrenches, Sockets, and a Torque Wrench to torque the housing cover bolts (25 ft-lbs)
Parts: Housing Cover Gasket, Gasket Sealer, 2-3 Quarts of Gear Oil (I run 75W-140 to 85W-140 especially on high mileage differentials, oh yea Valvoline Conventional or Durablend.
If you have a Limited Slip Differential you will need friction modifier, I highly doubt you have Limited Slip because not many people who got the vans opted for it, and since yours is a conversion van I am almost certain since most van converters rarely order them with LSD. But just to be sure check the white build sticker under the hood, should be attached to the underside of the hood.
1. Put a pan under your axle housing.
2. Take all of the bolts off except the top two, these you just want to loosen.
3. Hit the cover lightly with a hammer to free it.
4. Let all the nasty oil drain, then remove the top two screws and the cover.
5. Inspect the ring gear for any chipping, if their is chipping I recommend you have the ring and pinion gear replaced. Inspect the spider gears in the carrier also for any damage and replace if damaged.
6. Clean the old gasket off of the housing and housing cover.
7. Clean the shavings magnet, this magnet sits on the bottom of the housing on the inside of course.
7.5 Take your housing cover and paper gasket and try to find a way in which the holes align perfectly, then set aside the gasket.
8. Prepare the housing and housing cover by covering both surfaces with gasket sealer, then place the paper gasket onto the housing cover being sure that the holes align perfectly.
9. Install the cover and finger screw the bolts in.
10. Take out your wrench and just wrist tighten everything, then take your torque wrench (set 25 ft-lbs) and torque each bolt working in a zig-zag pattern.
11. For me, have a beer; but for you, grapefruit juice.
12. Fill the differential with oil, if you have a Limited Slip Differential be sure to put the friction modifier in first, then the oil.
13. Put the filler plug back in and then go for a ride!
Be sure to bottle the old oil and bring it to your local oil collector, in my case autozone.
If you have any troubles you can just PM me or email me and I will respond in the drop of a dime.