Need help downgrading TL-10 from 5.1

I have he TL-10 version (Gold) and I updated it to B313 5.1 lollipop a few days back but I'm not liking it very much, my phone becomes very laggy sometimes and I can't seem to find any way to downgrade it back to 4.4.2 Kitkat. I've searched online but can't find B300 transition firmware for the TL-10 although one does exist for the TL-09 version. Can someboy help me in downgrading it back to Kitkat. I've done a factory reset as well but that didn't help either.