The photo shows the original doorbell and base plate. The hooks of the base plate get easily broken off when replacing the battery. 

As a 3d model, this base plate is difficult to print in one complete part. Therefore I made it in 3 parts: a base plate with 2 rectangular holes and 2 separately printed hooks that you can insert in those holes.

The base plate should be printed with support because there is a small part that doesn't touch the bed.

The hooks are easily printed on their side. After printing, push them in the holes. A little drop of glue can be usefull to firmly hold them in place.