Use a bearing puller similar to the one pictured to remove the main shaft bearing.
After that press off 4th and 5th gear. It comes off as an assymbly so try not to drop all the parts.
4th/5th assymbly layed out
Now press out 3rd.
Here you can get an idea of how this all come apart. Make sure you lay things out in the order you removed them to keep track of what you did.
Clean everything out with brake cleaner. Be sure to check the oil holes in the main shaft for obstructions.
Take the syncro clip off the old one and slide it on the new syncro. Do this on all syncros.
Put 3rd back on. Bearing-3rd gear-syncro-syncro hub. Make sure you line up the notch of the syncro to the hub. Also note the direction the "U" in the hub is facing.
Press it on until you have a .002-.008in gap between 2nd and 3rd.
There is a partially cut tooth in the syncro sleave that must line up to that "U" in the syncro hub. Once that's on slide the other syncro then 4th on.
Slide the needle bearing and spacer back on.
5th gear goes next.
Followed by 5th syncro and syncro hub.
Press the 5th gear syncro hub back on.
Don't forget to put the 5th gear syncro sleave back before pressing on the main shaft bearing.
Remove the lock nut and spring washer, they need to be replaced.
Use a gear puller to pull the counter shaft bearing off.
I didn't have a better way so I pressed everything off at once.
Counter shaft layed out
You should replace these friction dampers while you're here.
I must have been getting tired since I didn't take any detailed pictures here. Basically it all went back on the way it came off.
Checking for an .001-.004in gap.
Stuffing 4th back on.
5th and bearing. After which replace the spring washer and nut (80lb-ft) and stake it.
If you are changing the diff remember these are left handed threads, turn clockwise to loosen.
Use a gear puller to remove the diff bearings, it'll look somewhat like this mess. (I had to grind mine down a little to clear the speedo gear)
When you press the new ones on make sure you contact only the inner race.
