If you do not fully understand the geometry involved in a trigger job I would suggest that you find a professional that does. Trigger jobs are very delicate work and if not done correctly can be dangerous and costly to correct.
Reducing your pull to reasonable weights will require more than polish, the angles of the sears should be altered slowly until the correct geometry is achieved, this will require removing them.
I generally encourage people to challenge themselves and learn new skills, trigger jobs are a different kettle of fish with the stakes a fair bit higher than a stock finish or simple repair.
Good luck!
Steve