it looks to me like this is in a basement with the wall the cabinets are on built out from the structural wall.
i think you could just take out the panelboard and install a smaller junction box in its place and relocate it somewhere else. it should not be real hard to route wires over to the new location. I think this is a case where you might be able to "fish" NM behind the cabinet wall without the normally required supporting and securing.
Or it might just be simpler to move the cabinets out of the way.