I have searched and read over a lot of threads regarding Frog Legs and the ZRa, and want to confirm something before I go ripping off my old caster forks.

I have a TiLite ZRa series 1 from 2008. My caster forks are the wide bearing type shown in this image:

I ordered the FL Unitines, and they shipped me what I believe is the correct fork, with two bearings in the fork assembly as shown in the right-most fork in this image:

I removed the caster and then removed the nut and washer attaching the fork to the stem (parts #13 and #14 in the upper image). From the TiLite image, it looks like the fork should just come right off. But it doesn't. It spins freely, and wobbles a bit with the nut removed, but doesn't come off.

Should I just use the awl/punch method to rip out the lower bearing in the fork since I don't need it anyway? Will something like PB Blaster help, or is there some kind of locking mechanism actually holding the fork onto the stem? Is there any risk of damaging the stem itself? I don't really care about the bearings in the TiLite fork or the fork itself, since I already have the FL Unitines on hand.