Hobbywing Xerun 150A Housing

This needs to be printed in something heat resistant like PETG or ABS, PLA will most likely deform due to heat from the ESC.

Glue the fan cover on the upper casing with CA glue.

Use the 4 standard small screws from the old case to fit the new case to your ESC, drop-in replacement. 
This case is designed for the Hobbywing Xerun 150A ESC, as seen below. While you are at it, it might be a good idea to replace the fan and heatpads.

Print Instructions

Make sure you split the STL into objects in your slicer, and orient them in a convenient way for your printer.
PrusaSlicer → Right click → Split → To objects