How can I remove new models from WotLK?

So I play in Retail, but found out some of my friends were playing here in Ragnaros so I joined just to have a little fun, the problem is I use the new models in retail and somehow those models are applying to WotLK, but it seems like the game doesn't recognize them too well so they are a bit weird.
How can I go back to the old models in WotLK?

Thats actually the new Wrath Client Warmane has released, you can find the old one on the download page, or you can click the link below and it will allwo you to download the old client without the new models.

(Magnet link)
magnet:?xt=urn:btih:b296ea8947b36c68f6e022f5a642ec c406ad8968&dn=World+of+Warcraft+3.3.5