You should be able to run Boot Camp Assistant and remove the boot camp partition...restoring your drive to its former single partition state, assuming it made that partition already.
To remove Windows from your computer:
Step 1
In Mac OS X, quit all open applications and log out any other users on your computer.
Step 2
Open Boot Camp Assistant, in the Utilities folder in the Applications folder.
Step 3
Select “Restore the startup disk to a single volume,” and then click Continue.