Proto 2000 FA2??

[McCullough]

I have an older Proto 2000 i think it is an FA2. It stopped running, took the shell off and discovered a blue wire that I believe should be attached to the motor had broken off. I'm not sure where it should be soldered in or how one pulls the chassie apart to search the underside of the motor. Can anyone lend a word of advise on how to rectify the prob? H. 28 views and no suggestion, can anyone help with an answer please.