Pls help me change it

I buy white ram,I cant use it. Could I change it? I cost all of gold,72G.
Pls help me!
My game ID:tangxinjiu
thanks !

You must also buy the riding skill I think. Should work then. Happy riding

I had bought the riding skil.but,I cannot use this white ram

If you are not a dwarf then you need to have enough rep to use the rams.

thanks a lot!
I had solved the problem With the help of gm