How do I play an artificial harmonic on violin?

I have a piece of music that requires artificial harmonics, which I'm not familiar with, The first is e flat (as in the flat of the e string); the stopped note is a flat (the a on the ) and I have no idea where to put my 4th finger to sound the e flat harmonic. The second is f natural (the f on the e string); the stopped note is b flat (again on the ) and again I have no idea what to do with my 4th finger. The first rehearsal is tomorrow and I really don't want to look like an idiot as the rest of them have been rehearsing for about a month already!