Hacking Noob question time! I have a couple questions about no ban no sky if someone wouldnt mind helping me

[Tyrantt]

I have a game dump from the gateway browser exploit thing, but how do i obtain the private header to use for my roms?

Also, if i want to update my current roms that i have on my sky3ds with the new private header, is there a way to do it without erasing my current save files?

thanks for your time and help guys