replace top mount bushes and bearings that way you dont need to take the springs off so no need for compressors. pretty simple tbh.
backs just a case of jack it up, undo the struts at the bottom, get a crow bar or simelar in and pop the springs out, remove strut top mounts from car, take strut top mounts off struts, put on new struts and then reverse with new strut and springs.
fronts a case of undo arb mounts, undo drive shaft bolt (seems that you dont always have to do this but on mine i had to as the drive shaft was resting on the subframe, only needs doing on one side think drivers but cant remember) undo the bolt for strut mounts hammer the bottom of the strut out, undo the top mount take out front suspension, then put new top mount bearings and that on the coilovers and reverse what youve just done.
i would give you a hand if i was close to you. if you get stuck you can always ask on here.

as for getting a garage to do it, ide say around 3 hours laour tops ( i did mine in my cusns garage in less than 2 and a long part of that was waiting for pages to bring me new top mount bearings)