In this video are clips of me and my girlfriend Sara drilling, mounting and leveling a plexi printbed on my RepRap Prusa.

I'm following the design outlined in Gary Hodgesons manual — garyhodgson.com/reprap/prusa-mendel-visual-instructions/ — but ended up ignoring the springs and used four nuts, using the lower two to adjust height of the bed. Doing this without a spirit level would be possible if you carefully run Z-axis over the bed, but when adjusting Z-bars and the other bars the magnetic spirit level was useful — just make sure to get one short enough to fit your bars.