How can I factory reset my family member's iPhone 5s?

My distant family member/relative recently passed away and she had an iPhone 5s that's still in good condition. Many already had an iPhone and didn't need an extra one, I did, so they passed it down to me.

Problem is I never knew what her pass code digits on the home screen were and neither did her immediate family.

So I'm curious, how do I easily get pass this?

Yes, I know I could just google it, but I just wanted to know in your opinion, what is the easiest way to do it? I'm asking because I've never been too tech savvy and wanted to know which way is the easiest.

Sure you can factory reset it but you will need the email login associated with the device or it will be locked.

If find my iPhone was enabled, you'll need her Apple password to complete the restore, this is something you can't bypass.

If you do know it or it wasn't enabled, you can enter DFU mode - and then restore it via iTunes