When you have saved your workspace as a template you can always access it from Workspace manager > Templates > Workspace templates. To be able to edit a workspace template, you need to be an admin in the template workspace.
Steps to edit a workspace template:
Navigate to Workspace Manager from Admin menu
Or if you a participant in a workspace navigate to "My workspaces" from User menu
Click on Workspace templates under Templates
Find the template by browsing or searching by keywords
Click on the three dots "..." next to the template name
Click Edit template
Login to the template workspace if needed
Start editing the template workspace either by:
Editing the page by clicking "Edit page" on the top right corner
Editing the workspace template settings from the Yellow top banner.
