Just did my belt - 107,000 miles
At 107k, I decided it was time. My input is
1. Take off the lower engine cover and work from under the vehicle.
2. before you lay down lightly set a 6mm Allan wrench in the lockback hole. Then when you are under it, you can pull down with a ratchet to release tension, then with your second hand, you can push the 6mm in to lock the tensioner.
I liked this better then trying to manipulate the new belt (which is stiff) and the tensioner at the same time. The old belt easily slips off, then Route new belt, release the tension on the 6mm Allan, pull it out and done.
DOUBLE CHECK the belt is in the proper grooves, just in case. 4 bolts to put the lower engine cover back on.
20 min total for me. First time I've done this.