Supplies: A couple of extra-long deck screws
Tools: a level, a length of pipe, a hydraulic jack, and a cordless drill with a screwdriver bit
Step 1: Place jack and pipe under front edge of bench and raise it a bit for support.
Step 2: Undo screw holding brace at wall.
Step 3: Place level on bench and raise jack until bench is level.
Step 4: Fasten brace to wall using extra-long deck screw.
Step 5: Repeat for additional brace.
The best part was that I never even had to move stuff off the bench. Thanks, Ed!