See http://www.fixya.com/support/t450981-remove_back_panel_maytag_neptune_dryer
The hardest part is removing the panel - the front panel, not the back. Take the door off. Then take off the front panel. Position the drum where you can reach the baffle to replace. Screw it in.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix tumble dryers.