Hi,
Here's a [https://helpandroid.com/how-to-reset-samsung-galaxy-grand-2/|link] that may help depending on whether you want to do a soft reset or a hard reset.
***Important:***
''Take note that doing a hard reset will erase all your data and downloaded apps. It will restore the phone to its factory default condition. Be sure to backup the phone to the cloud or a computer before doing this.''
''Also if the phone has a Google (or Samsung) account tied to it ***you will need to remember the account's User ID and password*** to access the phone once it has been reset due to the Google FRP lock (or Samsung account lock) being enabled by the reset.''