Here are the steps to factory reset your iPhone 7 Plus:

1. Go to Settings and select General.
2. Find and tap Reset.
3. Enter your Apple ID and Apple ID password.
4. Now the process to reset your iPhone 7 or iPhone 7 Plus should take a few minutes.
5. Once reset, you’ll see the welcome screen asking you to swipe to continue.

If you have any other questions or need further assistance, please let me know! 😊