[jelazar]

Check the old shock you removed. Sometimes the metal sleeve of the old shock lower bushing gets left behind when you remove the shock. Don't damage the male part of the wheel hub that the bushing sleeve is stuck to. I think those parts are out of production.

 

[jelazar]

It still looks to me like the old shock left its bushing sleeve behind on the hub, and that's why you can't get the new strut on. The sleeve is probably corroded in place, and the rubber tore when you removed the old shock, leaving the inner sleeve behind. If you remove that sleeve, the new coilover should slide on nicely.

I haven't personally installed D2 coilovers, so I'll defer if someone has installed tham and I'm wrong.

 

[jelazar]

You'll get better results with a true penetrating fluid, rather than WD-40. I would try a pipe wrench if you have one. It's ok if you gouge up the bushing with vice grips or other tools.

Heat from a propane or mapp torch may also help break up the rust, but be really careful you don't wave the torch around and melt something important.

As a last resort, you could carefully cut the sleeve along its long axis, then pry the bushing open with a screwdriver or something. But it will be very difficult not to damage the piece underneath that the strut mounts to. A few scratches are probably fine; it's probably already pitted with corrosion. But you wouldn't want big gouges or cuts that compromise its structural integrity or make it easy for worse corrosion to set in.

 

[jelazar]

I don't think you need to unscrew the bolt, unless it makes it easier to get a tool on the sleeve.