You COULD try to jack the top up and support it on 2x4s, if it is down. If up, you could simply lower it onto 2x4s.
Probably, though the simplest way, if it's down, is to loosen the tension at the adjusting bolt for that cable and then unscrew the lag screw where it's attached to the top. After moving the cable, reattach it and then restore the adjusting bolt position.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew