Sorry. My ignorance.
So, you can copy the code from the github folder I linked to above(or another sheet on github's repo if want/need). Copy the raw html and css text files from the repo. I recommend creating a new "test" game since you'll want to make changes and you WILL break the sheet as you work on it.
While you can make edits directly in the game settings console(btw the preview tab is near worthless, more about that later...), I would recommend using a text editor like notepad++ or similar to make any changes and doing a lot of copy/paste to your game settings console and save your changes. Open your game in another tab or window, open a sheet to see your latest changes.
Plan on refreshing your game and sheet quite often as you make changes. You can use your browser's Inspecting tool(right-click on something in your sheet and "inspect element") to look and temporarily make changes of the loaded html and css. I often use this method to tweak the sheet's code and then I go back to my editor and make the changes there, copy/paste to roll20, save, refresh game, re-open a sheet,... rinse and repeat until you get something to your liking.
Of course this all assumes some basic knowledge of html/css. Lot's tutorials out there and you really MUST read the roll20 wiki on
Building character sheets. MUST. There are some nuances of how roll20 interacts with and allows in the characters sheet code. The
CSS wizardry thread is also a wealth of info for any sheet author. the adventure begins... ;-)
