Backroll

I am trying a backroll but really battling to land them I keep landing on my bum after a full rotation am I leaning to far back and throwing the board to far away from the boat over my shoulder must I stand more upright and throw the board more in the direction I am traveling Please help What am I doing wrong

Don't drop you butt at you edge through the wake. Keep your hips up and you handle in tight.

If you can get a video uploaded it really helps a lot.

However, you might be bending at the waiste as you leave the wake - that causes a lower, faster rotation (dangerous by the way) and people that do that tend to land on their bums.

Get your hips out in front (of your belly button - not direction of travel). You'll notice a better pop and a higher / slower rotation.

Your body position when you leave the wake is how you will land. Matt's right, you're probably dropping your butt on the approach. Stand tall at the wake and after your rotation, look for the shoreline.

is it hard to do?

you could try letting go of the handle with your back hand that worked for me.

I concur with what steve said. The most important part of doing inverts besides edging through the wake is body position. I usually never recommend taking a hand off the rope unless the person keeps rotating to revert. Focus on body position.