Rear strut mount question

My dads 2002 protege DX had the drivers rear strut mount fail. It is so bad the strut actually fell through the mount and you can move it all around. I know how to replace struts and mounts, but i've never had one so bad the strut separated from the mount. Since the strut is not connected to the upper mount anymore, how do i remove it without the spring shooting out?

will i need to put a spring compressor on it while still on the car? isn't the weight of the car the only thing holding the spring in place right now?

I'm no expert, but I would jack up the car (jack stand of course), remove the rear tire and put the compressors on then and tighten them down a little, then try to remove the strut. It seems like the weight is holding it in there. If it come off while you are jacking up the car it shouldn't hurt anything (And the tire should protect you I hope) and then you can compress it.

There isn't a lot of force on the spring when the car is unloaded in the air, only when the spring is compressed. You will be fine.