Small Engines (Lawn Mowers, etc.): JD 345 main drive belt, sectional index, tension spring

Question
What is the best way to get the main drive belt (from the engine to the rear end) off? I have removed the tension spring and pulley but there isn't enough slack to get it over the front or rear pulleys. This is not one of the belts that drives the mower deck. Any help on this would be appreciated. Or where can I find a diagram on the net?
It is a JD 345 with a 54'' mower deck-20hp liquid cooled.

Answer
 Hello Kevin:

 I Usually Remove One of the Tension Idlers to Replace the Motion Drive Belt. Go to this Addy http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers 345 and Click Find. Then Select the Model from the Search Results Area. Then Select Sectional Index. Then Select Power Train. Then Select Drive Belt and Idlers. Hope this Helps. Let me know what Happens, Please. I am here if you Require more Assistance. Thanks.

 Good Luck

 Respectfully

 John