Power Window Motor Replacement

The motor on the driver's door of my 1999 dakota needs to be replaced. When removing the motor and regulator assembly, the regulator is in the down position putting tension on the spring. How do I get it detensioned? Do I hook it up electrically outside of the door and run it in the up position?

No one replied so I winged it. I removed the regilator and motor from the door, then I hooked the wires back up and put the switch in the up position. The motor ran in the up direction util the stop was reached. There is little tension left at the up stop so I was able to remove the three bolts from the motoe and hook the new one up. I did have to have someone hold the regulator in the correct orientation while installing the new motor. I then hooked it up again and placed the switch in the down postion and the motor ran until the down sto was reached. This allowed me to reinstall the motor and regulator assembly in the door. The whole job took about an hour. The istructions sent with the motor said than you could drill a 1/2 inch hole in the regulator gear and frame and install a bolt to hold it in the tensioned state whil swapping the motor but that sounded a little weird to me!