A simple question with a very complex answer.
Assumption 1) there is unused disk space after the partition, into which you can increase the size of the existing partition.
If the answer is no, then you will have to backup all partitions after the one you want to increase, then, starting at the last, and working forward, move existing partitions backwards into unused HD space (keeping the same partition sizes), then restore the backups into their respective partitions. That would leave unused space at the end (never the beginning) of the partition of interest.
If the answer is yes, no sweat. You have room to increase the size of the partition.
Assumption 2) you have made a backup of the partition you want to resize. Store the backup somewhere else; not in the partition you want to resize.
Assumption 3) you have a backup operating system to use to boot into if you get into trouble: i.e., boot form install disk, use knoppix, another Linux distro in another partition, or something similar.
Then, study the following info the these links on how to use parted to resize partitions.
http://www.linuxkp.org/en/content.ph...ts/parted.html
http://jamesthornton.com/redhat/linu...size-part.html
Note 1: since the partition table is written from the beginning of the partition, always change the size (increase/decrease) from the back end of the partition.
Note 2: always have a backup which you can restore, and a way to restore it.
Note 3:If the software on your partition is installed exclusively from the install disks, backup /etc, /home, and possibly /var. If things go wrong, re-install from install disks, then restore the configs in /etc, your /home, and anything in /var you thought needed restoration. Of course, if you've done on-line updates to your software, you'll have to do them again.
