On these banana jacks, the plastic part that is in front of the panel can be unscrewed. Only banana sockets I know that can be removed from the panel without unsoldering anything.
Thread is M6 × 0.75 mm. Nut is 8 mm across flats. Panel hole diameter 7.5 mm plus slop. Maximum panel thickness 4 mm, more if 0.75 mm of air is a good enough insulator.
This is http://www.teaser.fr/~amajorel/banana/, last modified 2012-08-15.