Diet is about 80% of the game. Really focus on the diet part of it. If you do the work outs like Doc posted you shouldn't see a lot of mass gain. These types of routines are designed to strengthen tone and promote lean mass as well as help with fat loss.
How long have you been doing these videos? What kind of results are you seeing, if you dont mind me asking? I bought a mountain bike and have been going to the gym a lot, and I have lost 35lbs. I have crohn's disease and have to take steroids, so I am constantly hungry and its a real battle to keep eating under control. I have hit a wall though, and it seems like I am stuck at my current weight of 195lbs.