Remember, your Woodpecker templates are just regular Word documents with super powers. So...you can treat them like regular Word documents.
To update a Woodpecker template: open it up in Word, launch Woodpecker, make any changes you need to make to the document or to your Woodpecker fields, and save the document ("File -> "Save"). It's that easy.
You'll likely also want to save the updated template to your document collection to ensure that your collection has the most up to date version of the template. Learn more about how to save your template to your document collection.