lifting to loose muscle bulk

more 3sport training, less lifting is the only way (other than starving yourself I suppose) to drop muscle mass in your upper body. Even then it probably won't be "easy" to do... your body isn't really set up for drastic changes I'm afraid.

Leegoo is partially right. Losing weight is never easy. However, I would argue that the body is set up for drastic changes, it just doesn't like to make drastic changes, hence the reason why both losing weight and adding muscle can be difficult. This is also why when you go on a diet, the body wants to get rid of muscle first because muscle is more "expensive" to keep around than fat. Muscle requires more nutrients and calories to maintain than fat.

Having said that, I would advise that you lose the fat first and see what's under there. You may not have as much muscle mass as you think you have. Lower your calories, but eat plenty of protein and continue lifting weights. Once the fat is gone, you may like your new, muscular-looking physique. However, if you feel that you need to lose muscle, well, that's easy - drop the lifting and swim/bike/run like there's no tomorrow.

If you just want to lose weight and don't care whether or not you lose muscle, then drop your calories and swim/bike/run like there's no tomorrow. If you want to add lifting to your training, use light weights and high reps as these will stimulate your slow twitch fibers but not do much for the fast twitch. Kettlebells are good for fat loss, but they are also pretty good at preserving muscle, so it's your choice whether or not you want to use them.

I agree with whats been said.  I lifted exclusively for 5+ years, and a few months ago I started really hammering tri training.  Since then, I've lost nearly 20 lbs, both fat and muscle, though I've kept my strength up pretty well.  You will loose excess mass naturally as you increase aerobic workouts if you keep your calories around a maintenance level.  I can think of ways to loose muslce (starving yourself, picking up a meth habbit) but if you're really looking to loose bulk, you will by doing sufficient aerobic exercise and by keeping calories down.