I would jack up each end, put jack stands under the frame so you have plenty room to maneuver. You can do one end at a time.
Like I mentioned prior, you may have to compress the front shocks with a jack to hold them in place to get the bolts started.
With the rear on jack stands, you will have to support the axle (if you get the shocks off without supporting the axle, it will drop down and the springs may fall out) with a jack and jack up and down to make lining up the new shocks easier.
Good luck, George