If you need the new firmware.bin and dont have python you can make a bat file to make the firmware.bin
Change I:\3ds\ to your own directory.
Code:
set ruta=I:\3ds\
bitsadmin /transfer mydownloadjob /download /priority normal http://nus.cdn.c.shop.nintendowifi.net/ccs/download/0004013800000002/00000049 %ruta%firm1.bin
bitsadmin /transfer mydownloadjob /download /priority normal http://nus.cdn.c.shop.nintendowifi.net/ccs/download/0004013800000202/0000000B %ruta%firm2.bin
bitsadmin /transfer mydownloadjob /download /priority normal http://nus.cdn.c.shop.nintendowifi.net/ccs/download/0004013800000102/00000016 %ruta%firm3.bin
copy /b %ruta%firm1.bin+%ruta%firm2.bin+%ruta%firm3.bin %ruta%firmware.bin
pause
Change I:\3ds\ to your own directory.