To print, you still need b-luds tpu pad. Instead of his case, you can print the changed one.

Print settings:

• Print with mount facing up and support for the bottom (good support settings needed). You wont see the support interface later on, since its on the inside of the case. 
• Layer height: 0.2 mm
• Infill doesnt matter, there wont be any
• Perimeters: 3

Any PLA or PETG should work.

Printed mine in quite cheap offbrand PLA…