Y-Belt Tensioner for Alunar I3 - Slight frame modification needed

Requires drilling ONE hole in the acrylic frame. I tried to do a no-modifications one, but the required size for it put it in the way of the heat bed.

Required:
All 3 screws and hex nuts from the original idler (m3)
bearing from the original idler (F623ZZ)
1 extra screw, same size as the others (m3)
1 extra hex bolt, to fit the screw
1 spring