I have a skill saw circular saw # 574. The orange plastic safety switch broke off, I can start it by pushing a nail into the orange part that is left, but a skill saw technician said that the switch was not necessary if I didn't want it. I don't want it. How do I disassemble the saw to get to that part. I have already taken out all the screws, and the saw blade, but can't get the plastic handle apart. I'd appreciate any help and references to diagrams. Thank you.