most generally lincoln ovens use DC motors on the conveyors. You only need to swap the two power leads to the conveyor motor to change direction. On my old 1100’s, you would swap A+ and A- on the conveyor control board to change direction. If your conveyor uses a tach instead of a hall sensor, you will need to swap T1 and T2 as well. User manuals can be found on the lincoln site that explain this in more detail.
one other thing i should mention. does the other oven have a place for the switch? if so, there may just be another lead laying in the equipment cabinet or the switch itself to change the direction. you would just need to connect this lead instead of the one that is currently connected.