How do I change my icloud

**I want to change my Icloud account because my phone is cracked and its covered with damages,i want to do this so i can trade my phone in for a different phone and for some reason it will not let me put in my email they always say my password or email is wrong but its not. Please help me change my icloud i really want a new phone. I already tried millions of times, So i cant figure out my password to my icloud because i forgot it but then i remember but then it said my icloud password was still wrong i dont get it.

If you want to know your data is secure and don’t trust the passcode to protect it when you sell it, connect to a computer and restore it.

Otherwise, power it off and then use any computer to remove the lock.

• https://support.apple.com/en-us/HT201441