Belt.jpg
Need an E10 Torx, mine was not a "security" type. (a 3/8" drive bar works well)
The tensioner pulley is #3 in the diagram. Using the E10 on the pulley give it a 1/8 to a1/4 of a turn and the tension will release.
While the tension is released slip belt off/on. (without pinching yourself

)