There is a gap between the jumper and the deck. Get your FEL and a chain around the pulling end of the mower and lift it up vertically. Then 2 people ought to be able to get at it.
If you remove each bolt and nut, clean with a really good degreaser and then apply RED Locktite liberally, available at auto parts stores,
torqueing to the recommended force for the size bolt used (www has charts) you won't be doing it again.