Uninstalling mods without the tools adminstration page

In my experiements with writing plugins I managed to enable a plugin that screwed up my installation.  The only changes that have been made to my installation has been in the specific mod directory and whatever else happens to the database when someone clicks "Enable" on the Tools Administration screen.

I've since removed the specific mod folder, but things still are messed up so I'm looking for specific database entries I can change that would undo that enabling - essentially disabling a mod directly via the database rather than using the tools administration page.

Can anyone help?