Ok, just to clarify I have never worked on a FOG trans, and it has been many years since I worked on any. But the following is pretty much basic shop class stuff. I have no clue how mechanically inclined you are, so I am going with the basics, no offense meant if you know this stuff already.
For step 11, make sure you have removed all the bolts and everything from the previous steps. I don't have a clue how many bolts there are, so I can't help you there. Sometimes you may find one that is hidden under grease. Believe me, this happens. At least to me.
Once you are sure they are all removed, tap the housing with a plastic or rubber mallet. You may need to get physical with it, if it hasn't been apart for almost 40 years it will act like it is glued together. Just do not use anything metal to hit with. Even though you are going to want to. And try to hit on the more solid areas (where there is the most meat). This is really one of those easier to show you than to explain things. Best bet is to tap around the mating surface, going around and tapping until you hear/feel it pop loose. Don't use anything to try to pry it apart. You don't want to risk marring the mating surfaces.
That should enable you to rotate the housing as per step 12. Again, I don't have a clue just how far the manual wants you to rotate it. I am hoping there are pictures with it.
Step 13 wants you to use a piece of steel rod with just a slightly smaller diameter than the counter shaft. Believe me, you do not want those needle rollers getting loose. They roll any and everywhere. We had to rebuild 3 speed manual trans in auto shop when I took it in '76(gee, I am really old) and those stupid things were a royal pain.
If you get this far maybe the rest will be a bit more obvious. If not then let us know. Remember, Ford wrote those manuals for mechanics in their dealer shops, not for us hobbyists. So what they think may have been perfectly obvious to the mechanics is not to us.
HTH some,
Russ