Step 1:
Open Steam by double-clicking its icon.
Step 2:
Enter Steam. (Most people fail this step.)
Now that you have entered Steam, navigate to your library and locate Counter-Strike:Global Offensive.
Click the icon and enter Manage Game.
It will lead you to a menu, which then navigate to the right side of the menu and find the Uninstall Game option.
Click Ok to delete CS:GO. (Hardest part of the step.)
Congrats, you have deleted CS:GO! The biggest struggle of CS:GO Players that had recently deleted their game is the urge to reinstall it again, this is why you have other alternatives such as CS:S, but the feeling isn't the same isn't it? It's much like smoking and then switching over to vaping.

Method 1 Complete.
Pros:
You have to spend some time reinstalling the game, better if you have slow WIFI, adding to stopping your urges of reinstalling the game.
Cons:
You still see the icon, urge increase every time you enter your library.

If Method one did not work for you, this one might.
Step 1:
On your keyboard, press Windows + X.
Press settings, it will open your settings.

Step 2:
Press Apps. It will lead you to a menu.

Step 3:
(To make finding CS:GO easier, use the search bar.)
Click on the name and it will prompt you to uninstall, press uninstall and confirm it.

Congrats, you've deleted CS:GO.
This method is slightly less effective than Method 1, but it is faster to do.

Pros:
Speed
Cons:
You still see it in your library
Doesn't actually delete the files, it's more like a placebo

A slightly more permanent method.
WARNING! : This section contains large amount of risks to your sanity!

Step 1:
Open Steam.


Step 2:
Go to the menu at the top-right, where it says your name, and click on “Account Details”.
Step 3:
Scroll all the way to the bottom of the page and click on “Delete My Steam Account”.
Step 4:
The next page will give you some information on how the process will work.
Simply put, there are 3 steps:

Fill in and send the verification form
Steam will send you a message confirming the process
After 30 days your account is deleted
RESIST! RESIST!

Pros:
Unless you make a new Steam account, you won't be able to play CS:GO again.
You are also unable to play DOTA 2.
Cons:
Where did my money go
30 days of resisting the urge

Arguably the hardest yet most effective method in quitting CS:GO.
Step 1:
go outside
touch grass

If you made it this far and the other methods do not work, congratulations, if you do this method, you are saved.

Pros:
Cures CS:GO
Gives you a job on the long run
Farming Master's Degree
Makes you immune to all sickness
Buys you a dog
Finds you a girlfriend
Dad comes back with the milk
Your mother loves you again
Gigachad visits your house and gives you a hug
You become a good chess player
You discover fun hobbies
You intentionally cancel your Netflix subscription
Your goldfish comes back to life
You're happy
Cons:
none