LyX ⇒ muthesis document class

[hooman]

Hi,
I have been trying to add 'muthesis' document class to the existing document classes on Lyx and I have not been able to do it. Is these anyway I can either add that or just change the existing document class by adding a latex code. I tried doing that by I could not get rid of the old document class so I was getting errors. Please help!!
Thanks,