Agreed on that black thingy. Did you liberate it from its track, or did you find it that way?
Sorry, just now looked at your pic. You have the nut holding the forward attachment of the motor off its stud. Now drill out those two dimples you see aft of that stud, above and below that 2" round hole. You'll find the other two mounting bolts.
You have circled pop rivets, which hold the mechanism, and will probably never need to be removed.
GB | 
