I sure can't move the tensioner with a damn 8" ratchet - you must be a gorilla.

And i don't use the 'pin' trick. I route the belt everywhere, but go UNDER the idler.
I then grab a LONG bar and move the tensioner, then pop the belt on the idler and then relax the tensioner.

OH, and I take the fan assembly out first, makes it way easier.