https://www.youtube.com/watch?v=yxRrpD_ewpE
found a repair video but haven't watched yet. Careful with gluing the pads pack. Crazy glue can be hard to use. Something else maybe or buy new pads.
I'm not completely sure what grease to use or even if you should (if you do apply sparingly).
Update:
the video is a bit long, but basically use a suitable knife to remove the pads, then a small phillips screwdriver. I don't know if the scroll wheel comes out but you'll at least have better access.
Here's a squeaky wheel gets the grease video (literally):
https://www.youtube.com/watch?v=PMXUUc1-IrA