Hold it at the angle that would be the same as if the vehicle is sitting level.
GENTLY pull it, adjusting the angle just a wee bit each time. Eventually it will come loose... you just have to play with it and be gentle.
Makes me CRAZY when it does this.
I'm talking pocket knife to cut the belt and .45 to shoot holes in the damn thing kind of crazy.
06 Rubi with some sort of double ended, chrome knobbed, cross threaded, infinitely adjustable, frequently breakable, worn out flammywhammers zip tied onto it.
It used to be a jeep thing... til that sh!t broke!