how to install additional language support

[gupta.kapilcs]

how to install additional language support if only one language is selected while new installation .
i have English language support this time and i need Russian,japanese,chinese,german and many more without a new installation.
how to do it?
help me out?

[gauravbajaj]

It will automatically do .., means at X login Screen, there is a tab for language support , just click on that & login to any lang u want ..

[gupta.kapilcs]

u didn't get me actually.
i mean to say that if we forgot to add some languages at the time of installation and without new installation we want to add new languages then what to do  as it do not have any other language to switch even in control center.
what to do ?
got me or i should give any clarification?
thanks