If you are talking about a counter-top type laminate, such as formica or similar, and it is attached with contact cement then I have found that a heat gun will soften the glue enough to peel off the laminate. I would start along one edge and slowly work across the entire surface. In some cases it is possible to laminate over the old. You need to be sure that the old laminate isn't loose at all, or your results will suffer. If you go this route then sand the entire surface with 80 grit sandpaper first.