Top of the shaft should have a hex on it, so you can use a couple wrenches to tight it up. The bushing should squish down a fair bit, to keep it from rattling. Bottom bolts just need to be tight enough to hold it in place, and not work their way loose.

 

This ^^^^^^

and you can use a couple wrenches or this tool (I have the tool - Ive done the shocks twice)

Lisle Shock Absorber Tool #20400 83045204008 | eBay

 

I used that tool to remove the old shocks. Such a cool tool! Worth 10x the asking price, for the amount of trouble it saves.

 

I used that tool to remove the old shocks. Such a cool tool! Worth 10x the asking price, for the amount of trouble it saves.

The Bilsteins have a female hex (uses an Allen wrench) at the top of the piston, and the nut is a 17MM, so no chance to use the tool for installation. Still worth the purchase just for much easier removal.

 

I've been known to use the Hot Wrench for removal......