If you want to make changes to an active or deactived workflow, you can easily move it to draft.
To move a workflow to draft, visit the 'Workflows' page and find the workflow you want to move. Select the checkbox next to the workflow name and click the cog icon, and then select 'Move to draft' from the dropdown. You can do this to an active or deactivated workflow.
Read more: Deactivating and reactivating workflows
