As I stated b4, there are no special instructions in the workshop manual, 1 sentence "Remove the interior trim." that's all , so it can't be that hard can it.
The wiper mechanism is attached by 2 bolts which are NOT part of the latch mechanism. You stated that a bolt is loose, so removal is not required, just tightening, however, I would probably put a thread sealer on both bolts just to make sure that you don't have to go back there ever again.
Torque settings for the bolts
Tightening torque Nut :
10~14 Nm (1.0~1.4 kgf.m, 7~10 lbf.ft)