Going from the gray matter, put both arms into the unit ,one to the left of the drum and one to the right near the bottom, left arm over the blower........... On the left side, the belt will go down from the drum, under the motor pulley, up on the right ,,Use your right hand and pull the Idler pulley to the right and lay the belt on the top of the Idler pulley...... let the Idler pulley return to the left slowly..........Viewed from the front, belt down on the left, under the motor pulley up and over the idler pulley.... continuing up and to the right , over the drum.........

Belt part link... http://www.repairclinic.com/PartDetail/Belt-Drive/1381519

Source: GE Model DBXR453GT