Step 1: Run timing belt thru profile. (Not shown)

Step 2: Take off top of T90 reverse unit. (Not shown)

Step 3: Run timing belt thru bottom of reverse unit & feed it around the pulley. (Not shown)

Step 4: Put top of T90 reverse unit back on. (Not shown)

Animation begins here

Step 5: Bring upper Power-Locks on 90x90 rail into gap on front of reverse unit.

Step 6: Slide reverse unit down until it is flush with bottom of 90x90 rail.

Step 7: Tighten upper & lower Power-Locks to secure reverse unit to rail.