STEP 1
- Click the "Library" tab at the top of the screen.

STEP 2
- Search for CS:GO on the left side in your Library of games.

STEP 3
- Right click the game and go down to 'Manage'.

STEP 4
- An extra tab should show up to the side, now navigate to 'Uninstall' and click it.

STEP 5
- Confirm your choice.

FINAL STEP
- Never come back.