How would you fix this suspension issue?

[Sasquach]

I have zero experience with suspensions on a Jeep. So I have a very basic question. If I want to change out the shackles, is it a matter of just removing the 2 bolts on each shackle in the pic below and slipping a new shackle into place?

The whole thing is under pressure from the weight of the Jeep right? So I need to put it on a lift and remove? Or can I just unbolt and replace on the ground as is?

Don't let me kill myself.

Make sure you put a jack under the FRAME on the end of the Jeep that your working on, A floor jack works good so you can raise and lower to line the bolts up. When you are pulling the old one off get the jack so it raises the frame just to the point that no tension is on the shackle you are doing (no sprng tension).
Good Luck.