Interesting. I've never seen those red plastic tools before.
I just replaced the serpentine belt on my 2013 last weekend.
It was more involved than most belts I've replaced.
I put a long wrench on the belt tensioner pulley bolt, then used an old motorcycle tie down around the wrench and sway bar (strap going around but not touching the CV shaft). This allowed me to keep the tensioner fully retracted without using my hands.
Even then I couldn't get the belt around the top idler. So, I removed the top two idler mount bolts and loosened the lower idler mount bolt. Which allowed me to rotate the idler assembly over to get the belt onto the pulley. Then I rotated the idler assembly back to vertical and installed the two bolts and tightened the third.
Even with all that, I had to use a breaker bar to rotate the crankshaft to get the belt tracking correctly on one of the big smooth pulleys before I fired the engine up.
Interesting comments about the "belt tensioner pulley bolt". I don't really understand this as this car does now have a belt tensioner, at least non that I can see. (uhm)
Tension is created by stretching the belt around all the hard mounted components.