First draw a map of the fan belt routing so that the new belt is installed in its correct orientation. The fan belt automatic tensioner needs to be drawn towards the alternator/front of the car to relieve pressure on the belt enabling it to be removed from the pulleys and idler assembly. The automatic tensioner is close to the alternator pulley.you may have to remove a splash shield under the car to ensure the belt is properly routed around the crankshaft pulley.
The answer I received was what I was already aware of.
I need to know how to replace the belt since engine mount is in way of removal/replacement of belt. 2004 Odyssey has motor mount that restricts belt from being "slipped" on. Thanks