Song Info and Song Lyrics (Erland Isaksson) plugins problem

Hello.

I continually get to the LMS web interface the following message at the bottom typical of any plugin update:

Plugins have been updated - Restart Required (Song Info, Song Lyrics)

However, after the restart, the message is always returned. If I go to the plugins page, and unclick to delete, the restart never removes them.

How can I safely manually delete this plugin and either run without them, or reinstall cleanly?

Thanks.

P.S. Is this the best plugin for song lyrics in LMS ?