So my son recently spilled soda on my 2014 MBP, but I cannot delete my iTunes / iCloud account from it. I brought it to my local Apple Store it they aren't able to do anything.
What do you mean by you can't delete your iCloud account? Could you be more specific?
https://support.apple.com/kb/ph2702?locale=en_US
Follow the steps in this article to delete your MBP from iCloud.