I am goimg to use my wife’s former 12 inch Macbook as my travel Mac. As she will no longer use it, I would like to “Nuke and Pave” and set it up as a new Macbook.
Can this be done by me (i don’t have any operating disk) or do i need to take it to my Apple store?
Thanks in advance!
No need to take it in to the Apple Store. Just boot into recovery mode (hold down command-R while rebooting), use disk utility to reformat the disk and reinstall macOS.
Just make sure you’ve got everything important copied off the disk first!
If the hard drive or SSD has been encrypted by the current OS, make sure you know the encryption password. You won’t need it right away but you will probably need it eventually.
Thank you both for your help. It is my wif’s old MacBook. She is not tech savy as I am the nerd in the family. 
I did not encript anything. Would Mac OS encript it?
Here are step-by-step instructions:
@Clay Here’s how you can check your FileVault settings. This would be On if your disk was encrypted. Apple FileVault Support Document
As I’m going through the same process with a MBA 2013 (yep still working fine, just a bit slow), I have 2 questions. Any help is highly appreciated.
do I need to Uninstall app such as Hazel? Or the license will still work after erasing the disk?
shall I go for APFS or keep MacOS Extended? (This question applies both for the MBA SSD as well as to my backup HDD)
Many thanks!!
PS - @Clay: a good hint I found is to de-authorise iTunes before erasing
The license will still work, but you do probably want to manually save out your Hazel rules before the nuke and pave.
APFS for the SSD. If your backup HD is a spinning disk I’d probably stick with HFS+ (And if this is a Time Machne backup, it has to be on an HFS+ drive).
Thanks!!!
Done!! And the Copy Carbon Cloner ones too! Don’t want to mess up with those 