Please review the information about what will be lost when you delete all data from the system. Deleted data cannot be recovered.
An Internet connection is required to format the system.
Any associated Nintendo Accounts will still exist after the system is formatted, and can be re-linked to Nintendo Switch systems and/or managed through http://accounts.nintendo.com.
Select “System Settings” on the HOME Menu.
Scroll down to “System,” and select it.
Scroll all the way down to the bottom of the menu, and select “Initialize.”
Select “Initialize Console” to delete all data in the system memory.
Read through the information on the screen, then select “Next” to continue.
Select “Initialize” to complete the process.