Henna Tattoo

Sooo I got a henna Tattoo done today. And I accidentally touch the henna paint as it was still wet. Lots are on my fingers. And behind on my acrylics nails too!  How do I remove the excess henna stains without hurting my skin and nails?  Also my actual henna tattoo is dodgy and looks rushed with parts out of place, how do I remove the little ruined bits with getting rid of the whole thing ?