[ubuntu] drivers ati mobility radeon hd 5165

Hello

I have a toshiba satellite l505-13e and ubuntu 12.04.1 lts 64 bit

Ubuntu can not recognise my graphic ( ATI mobility radeon hd 5165).

Search in some blogs how to install manualy the drivers but there was always a step were i got stucked because of an error or something.

Is there anyone who can give me the commands to install my graphic.

Thanks for the help in advance.

Regards