Having recently done the OME lift, I'll share my method:
The obligatory (which you've likely already done)-
The end you are working on should be up on jackstands, wheels removed.
Jack the axle up enough to take weight off the spring. Support the axle with jackstands.
Remove the trackbars and disconnect the swaybar (front axle).
This is the general method describing the front end
- Remove old spring.
- Attach the front end of the spring to the shackle (which is already attached to the frame) leaving the shackle-eye bolt loose.
- Attach the rear spring eye to the frame. If the fit is snug (may well be with the OME bushings) smear some grease on the bushing faces, then use a jack to slowly press the spring into the mount, paying attention to not tear the bushing. Position the jack at the lowest point on the spring for jacking. It may take a couple of goes before you get it spring eye positioned just right for the jack to push it in. Once you pushed the spring eye into the frame mount, it's just a matter of positioning the spring eye to get the bolt through, a hammer or screwdriver will be helpful in wedging it into position. Install the bolt, but do not tighten it fully.
- Position the spring under the spring perch and either jack the spring up to the axle (what I did) or lower the axle to the spring - such that the spring pack bolt fits into the perch hole. Install the u-bolts and nuts enough to take up the slack but do not tighten them all the way down yet. They will need to be loose enough to shift around to allow for adjustments on the other spring.
- Repeat steps 1-4 for the other spring on the axle.
- Once both springs are in place and properly positioned on the perches, tighten down the u-bolts to the recommended specs in a "1-4-3-2" pattern, evenly (see below)
- Tighten the spring-eye to shackle bolts but do not torque them down until you have the Jeep back on the ground
- Tighten the spring to frame bolts.
- Reinstall swaybar, trackbar (if desired), wheels, lower vehicle back to the ground and torque down shackles to desire ft-lbs.
It's probably more info than you needed, but I figured it might come in handy to someone else too.