I have watched many videos and read other install posts, but it seems like everyone drops the entire axle(front or rear) to change the springs. Could I get away with only lifting one corner at a time(if I disconnect the sway bar and track bar)? Or must I get the whole front or rear on jack stands?
Also, how much drop on the axle should I allow for to get the springs out(or how high must I get the frame from where it sits at street height)?

 

You MAY be able to pull the coil that way but very unlikely you'll be able to install a longer coil if your doing a lift

I just installed a teraflex 2.5 coil kit over the weekend and was very easy

1. Loosen ALL control arm bolts with jeep on the ground (if installing a lift)
2. Put one end of the jeep on jack stands on its frame - i used generic harbor freight jack stands
3. disconnect the shocks, swaybar links and abs/brake housing attachment
4. Use a jack to lift up one side of the axle, push down on the other side and spring should pop out

 

I do one side at a time. I do not remove the track bar. It all depends on the springs as for how much the axle must drop. Raise the frame about 5-6" and put jack stands under the frame. Remove the tires also. With doing that you should be fine. When I do mine (4"), I believe the frame is up on stands about 6" (maybe a little more) and when the axle droops the brake rotor is almost touching the floor. I haven't had to raise the opposing side yet; I've always got it done just by lowering the side I'm working on. Sometimes you have to help the axle down by pushing down on it. Like you mentioned, be sure to undo the sway bar as it will not let you get the droop.

 

I've had both sides in and out with the Jeep on jack stands. Track bar and drive shaft both stayed in place. The replacement springs were 2.5". Had room for another inch or two.

Getting the Jeep high enough and stable on the jack stands is the key.