[ubuntu] Extend root partition online/Offline in Ubuntu

Dear Team,

I am using Ubuntu 12.04.5 LTS and my root partition (normal partition not an LVM) is 90% Utilized.

Disk /dev/sda: 483.2 GB, 483183820800 bytes
255 heads, 63 sectors/track, 58743 cylinders, total 943718400 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00022bc0 Device Boot Start End Blocks Id System
/dev/sda1 * 2048 898437499 449217726 83 Linux
/dev/sda2 898437500 943718399 22640450 82 Linux swap / Solaris

Is there a way where I can extend my root partition online/Offline.If yes kindly share me the detailed steps on how to proceed further.

Regards,
RKJ