Managed to get the remaining rivets removed from rib T-1003C-R.
Since the tank rib was pro-sealed, it could not be removed in one piece. Cutting the rib into several small chunks & then carefully removing them took some time but, was the safer course to take. The last thing I wanted to do at this point was to inflict additional damage to the internal structure and/or the wing skin.
I need to clean up the internal skin of residual pro-seal & thoroughly clean it. Then I'll reshape the wing skin, re-clean the area & install the new rib.