Part of the problem is bro, your main "weight of pull" is the force required to push the sear off the striker. The only way to lighten that is to modify the sear or striker. Polishing those two pieces would help, and you could get handy with a file to make it smoother...
That being said, you do it at your own risk. Take it to a legit airsmith and have it done. Unfortunately trigger jobs on BB's are a bit of a lost art, and even I'm not sure enough of myself to offer to do it for you. talk to the boys over on mccarterbrown and see what you can find.