again, this would be more of a TJ forum question, but if its just a puck or spacer lift thats on it, it would be easyly enough removed. A body lift can also be removed easy enough,... but if it has a full on spring lift, I'm guessing your stuck, unless the the PO has all the old springs and parts. Gather some more info. if ya can, and take it over to the TJ guys. I'm sure they can help.
'92 YJ, 4.0, 5sp, 8.8, Tera 4-1, SYE, BDS 5" on 35's. 4.56 locked F&R. <><
'05 LJR, 6" long arm lift, 5.13's w/37 MTR's.
The YJ is FOR SALE! PM for details.