Starter/Starter Solenoid replacement instructions needed?

Sure, here is a guide to help you and I have a guide to walk you through the steps and the instructions for your van in the images below.

https://www.2carpros.com/articles/how-to-replace-a-starter-motor

1. Disconnect battery ground cable.
2. Raise and support vehicle.
3. Remove starter to engine brace and heat shields, if equipped.
4. Remove starter mounting bolts and lower starter. Note position of shims, if used.
5. Disconnect wires from solenoids, then remove starter from vehicle.
6. Reverse procedure to install.

Starter whining or a no-start condition on 1982---83 vehicles equipped with V8-379 diesel engines, may be due to insufficient flywheel ring gear to starter pinion clearance. To correct the above mentioned complaint, proceed as follows:
1. Disconnect battery ground cable, then raise and support vehicle.
2. Remove flywheel inspection cover and inspect flywheel teeth for damage. If teeth are excessively worn, replace flywheel.

3. Loosen both starter mounting bolts, then remove outside bolt and shim pack.
4. Measure shim pack thickness. If shim pack is less than .120 inch thick, add shims until total thickness is as stated above. If shim pack is already .120 inch thick, add an additional .040 inch shim to pack. Shim pack thickness should not exceed .160 inch.
5. Reposition shims, install outside mounting bolt, then torque both bolts to 30---40 ft. lbs.
6. Install flywheel inspection cover, then lower vehicle and reconnect battery ground cable.

The starter is located on the passenger side of the engine (right) down low near the transmission bell housing under the exhaust manifold.

Yep, insects are a problem sometimes. It sounds like the starter is shorting out, also check the battery cables to make sure they are in good shape.