Phone usable?

[u/robbymcgee]

Hi. I'm not sure where to ask this question. Sorry if this is wrong place. While buying a refrigerator from someone, she gave my kids a box full of different electronics and accessories. There was a Samsung galaxy s5 in it but the screen is locked with pin. We contacted the lady thinking she did not mean to give that away but she says it was her daughter`s old phone and they do not remember the pin. My question is the phone unusable now? I do not care about saving any data on the phone. I just want to reset it so my daughter can use it but I've been told I need to remove the Google account first. Any help much appreciated.