how to move a electric seat back with a bad electric motor

I don't think you can. You need a new motor, sometimes you can replace just the motor but often a whole new power seat track is the way to repair. It is not too bad to replace but the seat will have to be removed from the car and placed upside down to access the track assy. There are 2 bolts in the front of the seat and 2 bolts in the back of the seat that hold it down to the floorboard. Once it is loose you can rock the seat backwards to access and unplug the electrical connectors, and motor

I agree with david you cant move the seat if the motor is bad.

Be sure to check for any blown fuses And the switch function first

It's a long shot but if the motor runs it could be that the gears are stripped. You might be able to put pliers on the rod that the motor turns and move it.

There is a manual way to move forward and back on the track once the seat is removed with a large screwdriver

FOR THOSE WHO OWN A 2006 MERC GRAND MARQUIS AND THE SEAT BELT LIGHT AND WARNING COMES ON. IT'S NOT THE SEAT BELT ON THE DRIVERS SIDE. IT'S THE TENSIONER ON PASSENGER SIDE. AND IT A RESISTOR IN THE SYSTEM THAT'S BAD. IT'S A $2.00 PART . YOU WILL NOT FIND A TENSIONER ANYWHERE. BUT YOU CAN REPLACE THE RESISTOR.AND THE SEAT BELT SYSTEM WILL BE FINE.