I do my skull crushers on the ground because i dont have someone to hand me the barbell and its easier to get the barbell over my head. I want to start doing them from my flat bench, but cant think of an easy way to get the barbell over my head while in the required position.

any suggestions?

umm.. lay the bar on the edge of the bench above your head.. then lift up with a heave like your gonna bench it (in the air) and do a skull crusher.. whats the problem? if you are havin problems puttin it on the bench, put the bar on the bench,, slide the bar to one side and put a weight on the side real close to the bench.. then slide it over to the middle and put the other weight on it to balance it out.. its easy but my directions might be hard to folow, i dont know if this is what your are asking...

I just lay down backwards on a bench. Head at the bottom of the bench.
So sitting down on the bench, youre facing the bar. Pick it up and lay down and go at it, and when your done lower it then sit up and put it back.

**** lol, im stupid.. i forgot i do it another way.. what he said.. hehe ^^^

exactly. you do less weight on skullcrushers than bench press, so it should be no problem to grab the bar, lay down, and then get in position.

Just rest the barbell on across your legs sitting on the edge of the bench, then lean back and hoist it.