You'll have to update to 9.2 using a game, there is no other way.
(There technically is but more trouble than it's worth.)
Then Cubic Ninja/OoT for Ninjhax2 which can load rxTools and from there you can do everything you need.
Same reason why 8.1J are stuck, because they don't have a browser. On 7.x-8.x, no browser = you are stuck unless you can update to 9.2 with a game card update. Japan doesn't have any retail games that come with 9.2 and most likely never will, so they are stuck and require fairly complicated methods for updating to 9.2
European and North American, though... NA has -one- which is only certain specific revisions of SSB4, while Europe has 3 (Tomodachi Life (Rev02), Gardening Mama: Forest Friends, Cooking Mama: Bon Appetit!)