How to uninstall Coda plugins?

In addition the the accepted answer, you can just use ~/Library/Application Support/Coda/Plug-ins and then you don't even need to know your username. The tilda will substitute for the logged in account.

In the Finder browse to the /Users/yourusername/Library/Application Support/Coda/Plug-ins folder and remove the .codaplugin files you want to uninstall. That's it.

Oh, and be sure to replace yourusername with your Mac account name, usually it's firstnamelastaname.

Command + Shift + G for "Go To Folder..."

Coda 1

~/Library/Application Support/Coda/Plug-ins

Coda 2

~/Library/Application Support/Coda 2/Plug-ins