Preparing MacBook for sale

[BRISTOL86]

I'm trying to prepare my MacBook for a new owner, but when I try and erase the SSD in Disk Utility, I get 'erase process has failed'

The detail shows:

- Unmounting disk
- Couldn't unmount disk
- Operation failed

Can anyone please help?

 

[Schranke]

Are you in OS X while trying this?
Also this guide is useful https://support.apple.com/en-us/HT201065

 

[BRISTOL86]

Thanks, think I may have sorted now.

 

[Schranke]

Thanks, think I may have sorted now.

Your welcome