The video Bagman linked is good. But, you may want to consider what you're going to end up with. Pulling frets is sorta like pulling teeth - it's fraught with peril and doesn't leave an attractive vacancy. Even if you don't chip things up pulling the frets, the slots are still going to look a bit ragged. That gets more or less covered up when you put in new frets, but if you're looking at making a fretless 'board, it may be a lotta work that ends up aesthetically disappointing. Before you start down that road you may want to look into a new neck that either hasn't been slotted or at least not been fretted.