Pebble 2 (SE and HR) smartwatch replacement side plates and buttons.
The plates and buttons are printed as one part: this is to minimise printing costs. All you need to do is snap them apart by hand (no tools should be required but be gentle as the material is brittle), clean up the edges with a fingernail, nail file or fine sandpaper, and glue them on.
A newer version with the buttons & plates printed as a single all-in-one piece
is now available (at the same price).
A version with separate longer buttons
is also available.
The plates and buttons are translucent, but can be painted. There's a tutorial on how to clean and paint this material here: https://www.shapeways.com/blog/archives/28264-how-to-make-it-a-model-train-holiday.html
Please note that due to the nature of this design, the watch will no longer be waterproof.
You might also want to test out your chosen glue on the small bar piece which you won't be using, before you glue the plates to the case. Silicone applied in a fine layer works well.
There's also a version with longer buttons available