The ignition control module is attached to the distributor, which is directly behind the upper intake manifold on the back of the engine.
The module is connected to the distributor by two 5.5mm screws, real small stuff. These require a special socket to remove, the socket is less than $10.
Remove the wiring plug, it has a clip on the back side, lift the clip a little and pull on the plug, not the wire. Remove the screws, they are in opposite corners, pull straight down on the module and it will come off.
Use brake cleaner on a rag to clean the surface where the module mounts on the distributor, you can't get it too clean.
While you are at the parts store picking up the module, 5.5mm socket, (what makes this special is the depth and thin wall), brake cleaner, pick up a tube of "Dielectric Silicone for electric systems".
The dielectric silicone you purchased is better than the little dab that comes with the module, trust me, the stuff that comes with the module will get hard and loose it heat conductivity. (This is probably what happened to yours)
To install the new module, put a liberal coating of dielectric silicone on the metal surface and smear it around with your finger to cover all the metal. You want a good film of silicone. Now slide the module back into the distributor housing where you removed it from, the three spades go up into a connector inside the distributor. I you cant get the screws to start, the module is not seated all the way up or is in the wrong position, replace the screws, and the wiring plug.
You should be done.
This thing is a real bear to get at, I lay across the drivers side of the engine with my thighs on the radiator support and reach over the manifold with the left hand, and around the back of the distributor with the right hand.
I suggest you get a mirror to look back there so you will be orientated as to where things are.
After you do this a time or two it becomes easy, but take it slow and it will happen.
WARNING: BE CAREFUL NOT TO DROP THE SCREWS, THEY ARE NEAR IMPOSSIBLE TO FIND ON THE TRUCK, AND ALWAYS HANG UP SOME WHERE SHORT OF THE GROUND.
If you have any Q's, either post em here or PM me.
Ray