How do you delete a global attribute from a type?

Hey there...  This may be obvious, and I am missing it, but....

How do you delete a newly created global attribute after you add it to a type?

1. I created a global attribute and added it to the Part type.
2. Decided the attribute should have been a string instead of an integer, and with no way to redefine that, want to delete the attribute from the type.
3. Found the new attribute, selected it, and clicked the Delete icon.
4. Got an error message about the attribute being used in 8 layouts.
5. Can't seem to figure out how to remove the attribute from the layouts.