I know how to label shapes in draw.io by simply clicking on the shape and then typing, but how can I go back and easily edit These Labels without first deleting and recreating the entire text?
Double click on the shape to start editing with the label intact.
Usually double-clicking the text portion of the shape lets you edit it. Some of the shapes don't work this well and tend to just give you a handle to reposition the text instead (e.g. the UML Diagram Generalization arrow). If that's the case, right click on the shape and select edit. It should select the text portion for editing.
To make everything editable, go:
Edit -> Select All
Edit -> Lock/Unlock
For arrows with text the following worked for me:
- Left-click the arrow
- cursor turns into the "move" icon
- double-click the "move" icon
- your text will become selected and you can re-type/edit your text
On arrow objects there's a small handle you can double-click to edit the text. The other answers here didn't seem to work for arrows.