How To Access The Heater Duct
Here is a parts breakdown
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=MDE9700AYW
The following should answer your question.
http://appliancedigest.com/index.php?/files/file/473-16025911-maytag-27-inch-dryer-service-manual/
You have to join the site to download the manual but it is free and this is a very good site for manuals and other info for the appliance repair DIYer.