Go
HERE to find the Power Wheels Service Center nearest you.
I suggest that you bring the motor & transmission with you.
Also, if they follow the rules from F-P you may have to bring a "to whom it may concern" document that says you are buying them for a FIRST robot and you will not install them on a Power Wheels product.
In the Detroit area, the local dealer we use in McNichols Electric on 13 Mile near Beaumont Hospital.
For what it is worth.
Joe J.