Detach problem

[Kexlar]

I like what I see in the demo, but I would love to be able to play more than 2 mins, am I blind if so where the hell is the detach trailer button? I have looked every where I can while in the seat, nothing is highlighting, nothing is moving, I cannot click anything, having zero keys to look up in the controls is frustrating to say the least, I have been button mashing to disconnect the trailer but nothing works, I have checked to see if I am in the drop off zone, but with nothing to say I am or not.... My Truck is at a standstill.
Any help would be grateful.

[InfinitePotato]

If the drop off zone glows green, you should be able to move the lever on driver's left to detach. If the zone is not green, the trailer is not correctly positioned yet :)