How to completely destroy a plugin and it's contents?

So I recently made a plugin for studio that was basically like DEX. It could edit and view trees and what not. But when I updated it to try to fix the problem of it creating 2 toolbars and 2 guis in the core gui I got stuck with an infinite loop that couldn't be broken. When I mean infinite loop I mean I have: Removed the plugin from studio, updated the script to just print hello world, and had a loop to always destroy the gui in core gui. But I don't want to live with that for the rest of eternity so I need help to get rid of this thing.

No matter what I do, what place I go in there's always the gui there and the toolbar still there. All the scripts have been removed the GUI has been too and the plugin is just a plain script in a model so I don't get why it won't remove all the stuff.

The script went something like this:

local coreGui = game:GetService("CoreGui")
local tridentGui = script.Parent:WaitForChild("TridentGui")
local cloneGui

if coreGui:FindFirstChild("TridentGui") then
	coreGui.TridentGui:Destroy()
	cloneGui = tridentGui:Clone().Parent == coreGui
end

That script is something like the one in the plugin. I haven't created many plugins so I was definitely doing something wrong here. Anything would help. thanks

As I said tho, this script should have been terminated when I published the new script so I'm not really sure what's going on.