It is largely about having absolute, unshakable belief in your own ability and authority to do this. But if that's an issue, then I suggest hiring a reputable and experienced magic practitioner to do the job for you.

EDIT: Just wanted to add, there are lots of different methods from different traditions and religions, which I'm sure you're aware of, but in terms of simplicity I suggest looking at the Hoodoo tradition. There's a store and a forum over at Lucky Mojo where you could get some advice about binding and buy the necessary materials. http://www.luckymojo.com/ Gotta warn you, the Lucky Mojo website is topsy-turvy and a bit hard to navigate at times, but Lucky Mojo is very popular and well-known.