follow the guide and it should be okay 
just make sure you read everyrhing
just make sure you read everyrhing GBAtemp.net - The Independent Video Game Community
Sono
Welp, have you ever softbricked your SysNAND? I have softbricked my old3DS' SysNAND *FOUR* times, so I wasn't afraid to install A9LH Just make sure to believe in the success, and if something goes wrong, DON'T freak out! It's better to waste time rather than bricking because of rushing. Take it easy, make backups, sleep before attempting, and DON'T freak out
Just make sure to believe in the success, and if something goes wrong, DON'T freak out! It's better to waste time rather than bricking because of rushing. Take it easy, make backups, sleep before attempting, and DON'T freak out