[CentOS] Resize Logical Volume

Hello All,

I have a CentOS 4.4 running on a server with a 136GB hard drive, i have 
three different logical volumens and i would like to resize one of them 
( / ) with some idle space remaining in the hard drive. Can i do it with 
the server running or should i use the boot cd in order to do that?

I will appreciate any help and sorry if it´s a dumb question.

Regards,

--Ivan.