Can the belt on a swisher 44 inch tow behind mower be replaced without engine removal ?

I have a new belt for my 44 inch swisher tow behind finish mower.  The old belt is worn and starting to fray badly.  I hit some tall grass and stretched out the old belt.  I tried the to tighten the belt engage nut, and that worked, the belt started moving, but, I shut it down quickly when I noticed the fraying.  I cannot seem to get the new belt under the main motor pulley.  Is there a trick to sliding it on ?  Or, do I have to remove the engine ? Thanks.