One of those ideas mentioned should solve it for you. The battery shutoff is pretty easy--it should be pulled out. The circuit breaker in the battery compartment will be a little more difficult--there is a small metal device with 2 wires connected to it--follow the positive lead from the battery to the outside wall of the battery compartment to locate it. On the side of this device there will be a VERY small button--it may need to be pushed in to reset.
2015 38RSSA #7382
2005 TK3 #1869, 10 yrs of memories
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired