From the TJ Forum
The only thing that screwed off was the cup. The post stayed there. Our cups have a bolt, correct? At least the new ones I found do.
Further testimony about not removing the tower from the TJ forum. Don't mean to argue, just hoping to get lucky.
"Luckily, I never modified my bumpstop posts. Also lucky because when I did tear apart the suspension, the spacers came off without any issue. I was very surprised in the rustbelt.
The OEM bumpstop posts do not need to be modified to be installed so hopefully you'll be alright. I don't get why JKS puts that in the instructions. If they were modified by the previous owner, you could keep the ACOS based with the threads and bumpstop. Remove the locking ring and put the rubber spacer on the base without the ring. This should only equal another 1/2"-3/4" of lift (compared to keeping the ring and getting the 1.25" you mention).
Otherwise, you'd need to find a replacement OEM post and a welder.
The only risk is the ACOS base will extend your bumpstop rubber longer than OEM. This COULD limit your upward movement, but I suspect you'll need to extend the bumpstops longer than OEM in most cases so this added length may not be an issue."
I'm thinking unless I can find a replacement mount with tower or just the tower I'll end up using 3" springs + ACOS front and the current rear relo brackets to get this down to a more reasonable (for me) level. With TT/BL/MML, etc. I can clear 35s w/o fender mods at 4-4.5" lift. Just don't know which rate springs I'd go with since I haul a pretty good load on the trail.