As I said in response to your other post - the Sidekick does not use a "coil over" type strut, so a strut with springs attached is not offered - the coil spring sits between the control arm & the frame, not on the strut. You don't need a spring compressor to replace the struts, a pair of jack stands, a jack and the hand tools to unbolt the strut are all that are required.
After you put the car on the jack stands, put the jack under the control arm and use that to prevent the spring from unloading.