Claws are really easy to do as long as you don't let them get out of control in the first place. You need to get a proper pair of nail cutters like the guillotine ones that are for cats and dogs (Wilko's sells them for a couple of quid). You obviously need to look for the "quick" which can be hard when buns have dark claws but in general look to take off 2mm off every month.
One thing i have noticed is that bun is a great detector if you are about to cut the "quick", before you cut apply gentle pressure on the guillotine (not enough to cut, just to press), bunny will soon let you know if your about to cut the quick!
If you are worried about cutting him then make sure you have some Styptic powder on hand, and some cotton swabs just in case