I remember there being an R4DS Spring Removal Guide. I think it might help you since they should probably have similar slots for their Micro SD Cards...
Well I have a method for fixing the broken spring that makes your card work like a springless. I have done this to several flashcarts. It has always worked. I even fixed Vulpes Abnocto's M3 Real like this GBATEMPBLOG It looks complicated but really isn't. Try at your own risk but it has worked for me everytime.