It depends on where the noise is coming from, the motor actually sits behind the front firewall, and uses a linkage to rotate the wiper hub (which itself is responsible for the up/down motion of the blade). In the end, it may simply be more effective to take the whole assembly out, and access it off the car. It's not too hard - I just went through this a little while ago to reach my blower motor - but it may take awhile to figure out how to remove the assembly the first time. The second time goes a lot faster.

-anthony

p.s. if you disassemble the wiper linkages, etc., make sure you have a copy of the shop manual - it contains instructions for making sure everything is properly aligned. If you don't take the linkage apart, then don't have to worry.