There are a number of different chelating methods. The two I've used have been cilantro and chlorella and the Cutler Protocol (DMSA and ALA or ALA by itself). They both have good and bad things about them.
Others use DMPS orally or by injection. I can't comment since I've never tried it.
A search for chelation methods would give you more information about them. It's important to find as much info as you can before you begin any kind of chelating. Chelating is not 100% risk-free and research can help you do it safely.
My initial advice for you is that oral chelating should be done by frequent dose method. That means every 4 hours or less, depending on the method you use. It also means getting up in the middle of the night to take the chelator again in order to keep the effect going and avoid redistribution of metals.
It's also important to go easy and use one chelating method at a time, so you avoid overloading your body with released metals.
This is just a basic idea. Definitely find out more before you try a particular method.