Updating an existing document in your Document Collection is very easy. Simply open up the document in Word, make your desired changes, save the document within Word ("file" -> "save"), and save the document to your collection once again via the "Collection" page within Woodpecker (click the "Add current" button).

Woodpecker will give you the option to overwrite the existing version of the document in your Document Collection or to keep the existing document and add the new one as a separate document.