It's actually not possible to edit an existing workflow using the Workflows API, so technically this isn't possible. Creating/deleting workflows is supported, though, so as a workaround you could do something like the following:
Make the change(s) you want to the workflow definition, making sure the result complies with the Create a workflow API specification
Create new workflows using the workflow definitions you created above
Delete the old workflows
Because this workaround involves creating and deleting a large number of workflows, I wouldn't recommend this if you have the ability to instead edit your workflows in app. You'll be better able to preserve workflow history & statistics by making the edits in app, and there's a far smaller chance of something going wrong as well.
It's actually not possible to edit an existing workflow using the Workflows API, so technically this isn't possible. Creating/deleting workflows is supported, though, so as a workaround you could do something like the following:
Make the change(s) you want to the workflow definition, making sure the result complies with the Create a workflow API specification
Create new workflows using the workflow definitions you created above
Delete the old workflows
Because this workaround involves creating and deleting a large number of workflows, I wouldn't recommend this if you have the ability to instead edit your workflows in app. You'll be better able to preserve workflow history & statistics by making the edits in app, and there's a far smaller chance of something going wrong as well.