That's easy, though before doing that, please follow the below guidelines.

- Make sure its the addon in question that is the reason behind it.
Do this by disabling any addon except the one in question and it's dependencies.

- Collect required information
Bring a debug stack (BugSack or something) and information on how you encountered it.

- Make sure you submit the bug in the right place.
The link to the left saying "Bug Report" should take you to the right place