The shaft you need to remove is above the PTO shield. You don't have to remove any bolts, just use a screw driver to pry off the tin cover on the upper bearing retainer that you mentioned. Inside you will see a snap ring that has two ears that stick up. Squeeze them with a pair of needle nose pliers, and remove the snap ring. You'll then want a piece of 1/2-13 thread rod, about a foot long. You can thread this into the plug that is just ahead of where the snap ring was, and then just pull that out. Before you pull the long shaft, there will be an o-ring that sealed against the plug you just pulled out sitting into a groove cut into the splines. Use a small pick or screwdriver to get it out, then use the thread rod to screw into the long shaft and pull it out. From there, follow Donald Lehman's advice. If it doesn't come out easy, stick it back in and turn the PTO shaft just a smidgen and try again.