How do i replace the idler pulley and belt on my electric dryer?

Dryer Repair
1

The drum stopped turning on my dryer. The belt was broken and while replacing, we discovered the idler pulley was broken and laying under the motor. How and where do I mount the new one and position the belt?

2

The following should help
http://forum.appliancepartspros.com/dryer-repair/25860-dryer-belt-diagrams.html

WHIRLPOOL Whirlpool Dryer Belt, part number: AP2946843

Following may also help although the dryer case is different the belt install is the same.
AP2946843