Then, reboot your brain. Turn it off. Turn it on. Imagine your brain reading a book.
Next, read this poem. The poem will blot out the lyrics of the song (C*ll M* M*ybe) stuck in your head, and since the poetry doesn't have a tune to it, then it doesn't get stuck as easily either.
Last, but certainly not least, repeat the following:
If that doesn't work then you should probably have a lobotomy.