SOP for adjusting rear drum brakes/hand brake:

Back off the handbrake (e-brake) adjustment completely, then adjust the rear drums using the adjusters on the backing plate. Unsure what type you have but B110 have a square shaft that you turn to adjust. You need the rear wheels off the deck (use axle stands!! We don't want anyone getting squashed!), adjust the brakes on each side until they just stick and then back it off a touch until the wheel spins free again. Then adjust handbrake until travel is suitably short but not causing the brakes to drag. Job done