If you're not strong enough to lay the cabinet down, taking out the monitor could prove even more difficult.
If it's an "easy" one (that has handholds, and a mounting board) you are going to be armcurling the thing out of the front of the cabinet, on the board, and trying not to scratch/break anything in the process.
I would guess most 19" monitors are in the 70 lb+ range.
If the thing is bottom mounted to the cabinet, you may end up in a really bad position to be lifting anything, and have to hold it up while someone else unbolts it, and then armcurl it out of the back of the cab--again trying not to scratch/break anything.
I would just get a bunch of guys, rock the cabinet back as-is, and set it down nicely.
Nobody should be holding more than 40 lbs, or so, that way.