I had a faux button hole that I had opened by a tailor it was quick and easy. From the picture i see the weave of your fabric in between implying it wasnt cut originally but just sewn straight onto the material? My "easy to open" was tightly sewn shut with the same colored thread as the "hole stiching". IMHO take it to a tailor. If it simply needs to be opened he can probably do it while you wait. otherwise you will have to take it to him to make a working hole anyway.