The trick is to boot from a Live or Rescue CD (e.g. KNOPPIX). This offers all necessary tools for resizing operations. But be aware that this is always risky! Backup your data!
On command line, the tools are resize_reiserfs (for reiserfs, which is the SUSE default) and cfdisk. Read 'man resize_reiserfs' first, then you won't have problems.
EDIT: Sorry, didn't read you are using ext2. Just looking for the correct tool for this one
EDIT2: Ahh, it is called resize2fs. Should work the same way.