stretching leather pants

So I bought these leather pants for $16.50 from ebay, and well, they're just a little too small for me, which is not quite what I was hoping for, but it's the right direction because I want form fitting, body hugging leather pants. So here's my question: Is there a proper way to stretch out leather pants? Should I just wear them and push their limits by a little, or do I treat them with something or get an artifical stretcher or anything like that?