From the Signer editor:
How to navigate to the Signer editor
From a signature field:
How to navigate to the Workflow editor
Draw a new or select an existing signature field on any PDF to open the field editor in the right side panel.
Who needs to sign this field? dropdown. Hover over the signer you would like to reorder in the dropdown and click the edit pencil icon to edit the signer in question.
Adjust the ‘signer order’ field to reflect the order in which you would like this signer to sign. Note: from a signature field you can only reorder signers one at a time. Go to the signer editor if you would like to see and reorder all of your signers at once.