rear Bilsteins how to tighten top nut?????

Putting Bilsteins on my rig. Figured the fronts would be a pain so I did them first. When I got to the rears how do you tighten the top nut. The shaft turns as you turn the nut. The dust cover is flexible and not part of the shaft. If I could get an impact gun on them then I could just buzz them on but floor is right there.

Any DIY guys run into this?

Thanks JKaz