We didn't have the right tool convert for a while, but now we do. You can just email your request to igor.lebedev@boonex.com with reference to this reply/comment. We can only convert "paid" licenses though, not the ones that have been granted for free.
Mobile License gives your the _right_ to rebrand. It doesn't include a rebranding service, since it is more of a creative process that may be very different depending on your personal branding specifics.