Printing Information:

• Use tree supports to support the interior off the egg while printing
• Use a brim to improve the bed adhesion

The technique I used was based on this tutorial by EngineerNick:

The blender file is provided would you want to edit the model easily or simply see how it's done. Note however that I tweaked the resulting output to improve it for 3d modeling.

I also provided my base egg, I couldn't use my Math Egg as I needed one with nice topology so I quickly remade one from scratch.