I've got 30+ years of automotive and aerospace mechanical engineering experience and was a Minuteman missile maintenance officer for three years with one of my duties being squadron safety officer. I've also been working on cars since I was a teenager.

Place the jackstands under the control arms and the weight of the car will keep the springs compressed - no need to safety chain the control arm.

Since the struts have 360 psi of gas pressure they naturally want to extend, but once you remove the top nut you can probably push the shaft down and tie it up with a a couple of loops of HD string.

If the dust boots are broken or the jounce bumpers are deteriorated the strut will need to come completely off, but that's just two more bolts. Chances are if the top mounts are deteriorated, so are the dust boots.

Duke