Help with unlocking a locked phone

So long story. I have an iphone (unsure what model at the moment) that i use specifically for work purposes only (photos, notes, etc) i recently had a bunch of young children from the family over and now it it completely locked. was wondering if there was any workaround to unlocking it as it is my father in-laws apple ID. again it is strictly a no-service phone i just use to take photos and notes etc. Can i do this via iTunes on my PC or what?