If you really are a mechanic, then you should have absolutly no problem at all. "rebuilding" the starter sounds like more work than it is. Did you read the write up and look at the pics? Removing the starter takes ten times as long as the actual rebuild of the starter. Once you have the old contact out you will know if it needs replaced. Basically, if its worn down more than half way, you found your problem. Dealer will stock the part. I gave the part number in the write up. There are 2 contacts in the starter, only one actually needs replaced in most cases. Dealer has them, 4crawler has them, and some parts places stock them. No worries about getting the parts.

Theres no reason for the truck to be down. Worst case scenario, you take it apart, and the contacts are fine. Bolt it back together and reinstall. From what I've seen, contacts usually last about 150k miles. Or around 10-12 years.

1993 FSM says the starter relay is located in the number one junction block on the driver side. (fuse block in kick panel) Peek your head under there and see if you can find it. Doesnt say anything different for auto or manual.

On my 88 V6 5 speed, the starter relay is on the passenger side fenderwell. Its clearly labled starter relay. Its silver in color. Bolted with one bolt to the inside of the fenderwell.