Looking to reset iPad 2 to factory setting but can’t recall passcode

I have replaced my iPad 2 with a iPad Pro and would like to give the old iPad to someone outside of my family. I need to reset it to factory settings and have already transfered everything to my new device. Following the instructions in Settings I need to enter the 4-digit passcode I haven’t used since I set up the iPad in 2011 so I have no idea what it is. How do I reset this or just delete the iPad from my iCloud/iTunes accounts?