change my character how?

i have seen in movies people change the wind rider to a plane and there characters to ragnaros in the middle of orgrimmar.?

how do i do this :ops:

- u download and start your own wow-server and play god

-or-

- u search and connect to a private fun-server and ask the owner to do it

u cant do this on blizz-servers...

i think they only changed the model!