Eradicating Fish LIce?

I noticed a small brownish 1/4" parasite attached to 
the bottom of a rather healthy looking cardinal tetra.  
I am told that it is a fish louse. Nothing new has been
added to about 2 months.......

I've only seen one of these things. My plans were 
to take the affected fish out of the tank and pull the 
louse off with tweezers.  Then possibly treat the affected 

Will treatment affect the live plants and other fish in 
the tank??  What kind of treatment should I use?

Any suggestion or experience with Fish Lice???