Can you actually hear the motor running?  You're going to need to get that front panel off the find out what's going on.  A belt replacement certainly can be done if that is the problem.  The instructions are here on the website somewhere but I think I have a copy of them as well.  You must remove all of the hoses from the pump in order to replace it and loosen (but not remove) the motor mounting bolts.  Investigate further and let us know what you find.

It most assuredly must be the belt.  What you'll need to do is get the panel off, remove all the hoses from the pump (mark them if necessary).  The clamps are a pain to get off most of the time and I when I did this job recently I replaced them with easier to manage band type clamps that tighten up with a socket or slotted screwdriver.  If you use these be sure to get them good and snug, but not so tight that you would break a pump port.  Then you will locate a socket of the proper size and loosen up the motor mounting bolts.  Attached is a diagram on this.  The belt I bought was from ACE Hardware and it was a 3L310 General Utility V-Belt, ACE part number 22523, made by MBL.  You will remove the broken belt and then thread the new one on over the transmission and up around the pulleys.  I put mine on the motor first, it is more difficult because you have a tight tolerance there, but it can be worked over the top of the motor pulley and around the pulley, then thread it around the transmission pulley, while doing this you may need to move the motor in (to the left) to give some slack for the belt to get over the transmission pulley.  Pull tension back (according to the instructions) and tighten up the motor mounting bolts leaving 1" of in/out deflection on the belt, you want it neither too loose or too tight as it will over stress the pump/transmission bearings.  Please let us know if you need any further assistance and best of luck :)