You need to have this to reflash it:
Another flashcard (R4, Acekard, DSTT, etc.), a DS Phat or Lite (NOT DSi!), and this update file.
Then, you need to do this:
1. Put the update file on the another flashcard;
2.Put that flashcard in a DS Phat or Lite and run the file;
3.When prompted, take...