Select 'Update & recovery'
Scroll down to 'Advanced startup'
Select 'Restart now'
Advanced options -> 'Startup Settings'
Hit 'Restart again'
Selection option 7, 'Disable driver signature enforcement'
You can now open up your device manager and install your printers drivers. You can find instructions on how to do this here.
Pictures by How-To Geek
Last updated: Dale 27/11/13