How to add a character sheet to existing game

I have started playing in a star wars legacy game. My GM has added me to the Gm list. I am trying to add the pre existing character sheet on Roll20 into our game, but i can't seem to figure out how without creating a new game. I have checked out the wiki on what to do with no help.
For an Existing Game
To change or add Character Sheet, the GM should visit the Game Settings from the Settings dropdown on the Game Details page. In the Character Sheet Template section, select a template from the dropdown. Pro subscribers can also choose Custom to enter their own HTML and CSS. Finally, you need to click the (Save Changes) button found at the bottom of the screen. - Roll20 Wiki

when i go the the dropdown on the game details page, i do not see the character sheet template section. can i get any helpful advise please as this is my first time using this system. 

I think that wiki must be out of date. Click on the settings button on the game details page, then click on game settings. This will take you to a new page where you can set the character sheet to use.

there isn't anything to click under game settings that would take me anywhere. 

Game Settings

Token Bar Colors + Display Settings
Bar 1: Bar 2: Bar 3: Status Marker Position: Top (Default) Bottom Left Right
Deck Size

video+audio chat tech. 

This is all that shows up, unless im looking under the wrong settings

ah. You're looking under the settings menu in-game. Go to the game details page (the page that has the game forums and the join button on it).

Randall P. said:

Token Bar Colors + Display Settings

Bar 1: Bar 2: Bar 3: Status Marker Position: Top (Default) Bottom Left Right
Deck Size

video+audio chat tech. 

This is all that shows up, unless im looking under the wrong settings

You're describing the My Settings tab of the Sidebar, which is in-game. The Settings Page is accessed out-of-game, but it can only be accessed by the Creator of a game, and not a Co-GM. I've clarified this within the Choosing a Character Sheet section of the Roll20 Wiki, which you quoted in your original post. Thanks!

Thanks for letting me know that it can only be accessed by the creator of the game and not by a Co-Gm. Ive read over the wiki and it doesn't state that information.  

Randall P. said:

Ive read over the wiki and it doesn't state that information.  

I added this information within the 'For an Existing Game' section of Choosing a Character Sheet. The Game_Management#Settings already makes it very clear what Co-GMs can and cannot access. If you see any other sections of the Roll20 Wiki look like they should mention similar information, please let me know. Thank you.