Sold a Hacked Switch, How should I reset it?

Ever since I've had this switch I have kept it in airplane mode and have hacked it. I sold it to a coworker and he wants it factory reset. My question is:

To avoid this switch getting banned How should I reset the switch, if that makes sense?

Like is all I have to do is reformat the SD card and reset/reformat the switch so it wipes any tracks of it being hacked?

Or is there more to it, so when the coworker creates a Nintendo account they don't get instantly banned?

I have NAND backup of 7.0.1 but the switch is running 8.0.1

Thanks for your help in advance

 

ok thank you