Projects and creating a credit note

Hello

Is there a way to raise a credit note against a project that is set up?  I have raised an invoice, back in Nov, and it has now come to light that we need to raise a full credit.  I would to make sure that once raised, there are no income costs against this project.  But I can't see how to add a credit to the project, and if I raise a customer credit note I can't see there is anywhere to allocate it against the project.

Thanks

Paula