Right managed to get the belt off by using a large screwdriver. Pushed it passed the belt at the further point of the tensioner I could and pushed forward. Managed the push it enough to get the belt off yay. Just for your ref Steve there is absolutely no chance from what I can see of using that bit circled and pulling back.
Next issue the pulley bearing is so f*cking tight its untrue. I am pretty sure He-Man himself would have issues with this bad boy. Had tried with all my strength but it just wont budge

Any ideas other than the power of Greyskull ?
Am I correct in thinking you need to put a spanner on the bolt that has all the little teeth on and push forward ? Looking at the new bearing the thread indicated you screw on in the normal clockwise direction to tighten therefore I am pushing it in an anti clockwise direction. Hopefully this makes sense.