well..you'd 'want' to replace the struts....you dont have to but disassembling the strut assembly isnt the most fun thing in the world so the less you have to do it, the better
as long as everything comes off easily..no stuck/broken bolts or anything....its pretty simple..disassembling the strut assembly is kinda dangerous....I hate spring compressor's, so my method for this is to take off the center nut while the car is on the ground...the weight of the car absorbs the pressure of the spring as you slowly jack it up....the new spring should be short enough that it doesnt need to be recompressed...and if it does just throw the assembly back in and put a jack under the control arm and jack it up guiding the top of the piston through the hole in the chassis...that's the safest way I've found and I've done it a bunch of times..... other than that, its pretty straightforward....