I can not find a clear step by step guide on how to completely remove all data, apps, cache from my Mac (to give it to another friend), but keep a certain folder that I can not backup otherwise (it is 40 GB and we are far from home).
I have a MacBook Pro running macOS Mojave. I have 1 folder on the Desktop, and I want to remove all the data from the Mac including all cache and apps, and leave this folder there.
We can and should keep the macOS Mojave as I just downloaded it.
I want to really remove everything since it has a lot of garbage, cache, and private keys, etc.