If you want to get a .3ds you can try this.okay thank you I hope Groovey CIA on the final release can dump demos on 3DS format and if you can ask somebody has acknowledged please tell me when you know
Decrypt the .cia demo using decrypt9 and then using Asia81 packhack on your pc extract the decrypted cia. Then use 3ds builder to repack the content to get a .3ds file. Then convert it to .cia using Rikus tool which should make it region free.