Generally speaking, most people will uncouple the trailer before they extend the stabilizer jacks so that is what I recommend first. That said, if you are having trouble getting the trailer high enough to release the hitch ball from the coupler then you would just need to use a stand of some sort like the Valterra Trailer Jack Stand part # A10-0900 which offers another 8" or so of lift.
If the trailer lifts the hitch ball on the vehicle when you raise it then you may need to jump up and... view full answer...