The BT3000 actually has TWO v-belts! Here's a link at the end of this solution to an exploded diagram. Basically you have a major disassembly, but it really isnt that complicated.
More great info on the BT3000 is available from the web site http://bt3000.com/
I have a BT3100 saw, and it is a good tool, but does require attention in maintenance procedures, but Ryobi did outline the necessary steps in their manuals. The above website also has the owner manual if you need one.
- Unplug saw
- Remove the blade
- Lower mechanism all the way to the bottom
- Flip over saw and lay on it's top
- Remove the blade guard panel opposite the motor
- Unbolt the motor assembly and remove the belt cover
- Replace the broken belts
- Re-assemble (be careful not to cross-thread the bolts in the aluminum housings!)