I am currently trying to uninstall Avast, however I simply can't because I forgot the security password (not the ACCOUNT password)

General
1

I’ve tried everything I can, but I’m unable to change it. This is my last resort, so any help would be much appreciated.

2

Its hard to suggest something, if as you say you have tried absolutely everything, can you be a little more specific.

Have you tried this:
Clean Reinstall - 1. - Download the avast! Uninstall Utility, avastclear.exe Avast Removal Tool | Download Avast Clear | Avast and save it to your HDD. Make a note of the steps required or print the page.
2. - Download the latest Avast off-line installation file for your Avast Program.
3. - Follow the instructions in the link in 1 above.