Hacking NAND backup on 10.7 FW?

[Keylogger]

Hello,
Is there any way to backup my SYSNAND on FW 10.7 ?

I want to downgrade but if the downgrade fails, I'll have to format the 3DS and I'll loose all my save data.
So I want to make a NAND backup before downgrading.

 

[daxtsu]

Only with a hard mod. Software NAND dumping requires ARM9 as far as I am aware.

 

[DaRk_ViVi]

Same problem here.
If I go on with the format (with TinyFormat), what will I use and can't get back?