I already have a CFW, It's just every file over around 300MB that I try to move to my 3ds gives an error so I can't find something useful for me that allows installing backups "on the fly", so when I saw this I thouhgt could be my solution but there's the problem that many people report of corrupts SD using this and on the other hand they haven't all possibilities of backups as .cia format has... Maybe this is not what I've been looking for =/First you need CFW, follow this.
After you install a cia you can delete it or you can use ftp to access the sd wirelessly