My Craftsman 3/8 drive, 10 mm, 12 point fit okay on the bolt. The problem is clearance for the socket/ratchet/torque wrench on the rear bolt near the spring pad.

Other advice on the forum here is to remove the upper nuts, compress the piston and maneuver the shock tube outside of the wheel well to provide clearance to the back bolt.

I had a harder time getting a thin (ish) 17 mm wrench onto the lower nut in order to free up the upper lock nut to release the piston from its upper mount. Soaking in penetrating oil prior to starting the work is recommended. My Craftsman box end wrench was a bit too tall. Oh - and the Lisle brand shock absorber tool from O'Reilly Auto parts that fits "most cars except Ford" doesn't fit the 17 mm Mercedes nut or the Bilstein post. A small crescent wrench and a 17mm box end worked fine for loosening and tightening.