Geeze, put the XJ up on front jackstands, right under the firewall area back where the doors start, put the jackstands under the frame rails. Remove the tires/wheels, unbolt the shocks, take the little retainer clip out on the bottom of the spring. Let the front end droop then put the floor jack under the drivers side axle right under the control arm and pump the jack a bit, the passenger side axle will drop even more as the drivers side goes up and the spring will just about fall out so watch your toes and fingers. Install the spacer and put the spring back and the clip back on then repeat on that side only this time you will be doing the drivers side by pumping up the passenger side. Once both spacers are in reconnect the shocks, put the wheels back on and you are done. Think of it like a lever...
If you start pumping the floor jack and the XJ starts lifting off the jackstand STOP, you missed something, actually I missed something, disconnect your front sway bar that will allow more droop.. darn it's been a while.... I have two TJ's to do next weekend, at least I won't have to deal with leafs. Those coil spring compressors scare the heck out of me and they are tedious to use without an air ratchet and the compressed springs make me real nervous...
Oh, reconnect your sway bar or better yet put a set of JKS quick disconnects on there, those are downright handy. The XJ is really not safe to drive with on public roads or hiways with the front swaybar disconnected.
Thats about all I can think of, like I said it's been a while since I did my last one.