You don't need a spring compressor. Just loosen the big strut nut, remove the mount nuts and raise the car. The strut mount will come out and you will then have to remove the strut nut and pull down on the strut shaft to get the old mount off. Put the new mount on top, paying attention to it's orientation so that the studs will go back in place. Screw the strut nut on finger tight and then lower the car SLOWLY while guiding the mount into position.

I do this with a lift. With floor jack raise the car underneath the center crossmember for this. A reliable helper to lower the floor jack while guiding the mount in place will be a big help. I can lower the car in increments with the lift and jockey the mount in place, but even with a lift, a helper to lower the lift will speed up the job and do away with the frustration of getting the car in the perfect position height wise.

Good luck with it.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

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