Easy to find... see the other help.... It's held in place by a single torx screw.
If you install the 3BAR before the tune you'll get 2 DTCs, a CEL and a wrench light.... the tune loader will clear them... but takes a while...or at least seems like it when you want to go drive... LOL!. (what happened to me... no other glitches) The 3BAR does not have to be installed to load the tune, which I verified with LMS.... It's possible that loading the tune first would avoid this... not sure