Only thing you can do is decrypt the fat16 partition of your current 9.6 emunand (don't worry, it doesn't have to be in a bootable state to do this as long as sysnand still works.
).
Then use a program like WinImage to open the fat16 image and extract the data, private, and dbs folders. Then backup your 9.6 emunand (because gateway may still release an update to fix it...Unless your on a n3DS, then you're ***ked and it will be a long *** time before you can use that copy of your emunand again.
and inject a copy of your sysnand into it.
Then manually update that new emunand to 9.5 via CIA files (as long as you do this while in emunand, you won't get bricked). Then extract and decrypt that copy of emunand (rxTools is your best bet here. Don't bother with the time consuming xorpad stuff.
) and put in the files you extracted from your 9.6 emunand.
Then you succesfully transfered your NNID and other info to the newly created 9.5 emunand.
Long story short you'll have to search around and ask questions because I don't have the time to fully explain the process. Needless to say you are in for a bad time. Might be easier for you to just wait for Gateway at this point. Unless you are on a n3DS, then there's a legitimate reason why you should really try and do what I just said.
But for the n3DS you have to wait till Karl/OSKA gets release for it as there currently is no xorpad/decryption homebrew for n3DS nand/emunand yet. So your basically ***ked for awhile.