This one is hard to find. Options, Settings, click on Spyware Scan in the
left column, then find the threat in the right pane.
When I just tried to remove one such threat, the Save button wouldn't become
active until I also changed the checkbox for displaying scan results--do
what you need to do!
I think you then need to do a scan and remove operation--you can't just go
from ignore to remove directly.