What is the best way to get rid of lead paint?

To remove the paint yourself is opening a pandoras box. In many localities you are required to get the proper permit and have a qualified contractor do the work. You are not allowed to do the work yourself in these areas. They do this because it is a very meticulous job and if not properly done the contamination from your cleanup is actually more likely to end up in your son. A very safe way to minimize the danger is to repaint with a good quality modern paint and then not allow your son to chew on the walls or trim. This project can get so out of hand you may be better off selling the house rather than trying to do the job yourself.