My rabbit has needed clipping since she was just a baby, she was born with seriously misaligned teeth and won't chew on toys or much hay because of it.
I have one vet that recommended clipping them (nail clippers, etc) and another that recommended having them filed with a low speed power tool under anesthesia. The latter can be expensive (Around $100 USD each time), but if you have the funds and don't want to do it yourself, I would do that.
I know a person who uses a dremel tool to file her rabbits teeth, just be careful if you do this because the noise may scare them and if they bite down, the disc can hurt them.. afterall, it's a power tool.
I have more often than not, clipped them myself at home or had them clipped by one of my buns vets. If you do this, maybe have somebody experienced with it do it first so you can watch.
You don't want to have a tooth break, it can possibly cause infections. If you do feel comfortable clipping them yourself, make sure you always have the clipper straight along with the tooth so it clips the tooth and doesn't put too much pressure on it elsewhere and break it.
You can get a nail clipper with the clipper on the side, which has helped me a lot. >>>>
http://www.utopiatools.com/4-Sideways-Nail-Clipper.html