Once you have successfully uploaded a Google Doc template, you might want to change some of the wording or the aesthetics. To do so, click on the Google Doc template, click the edit button, then the pen button above the first page of the template. This will pop open the editor window.
This editor is almost identical to the one you experience in the Google Docs editor provided by Google. Make the changes you would like to see made to your template and click the close button in the top right corner. The template will save automatically and you can continue building out your template.