My root partition capacity is not enough. How can I resize it?

My root partition capacity is not enough. How can I resize it? -- Linux general technology-Linux technology and application information. For details, refer to the following section. I am using an open suse 11.1 single system. Now I find that the root partition capacity is not enough. I don't know how to resize without losing data. The level is too bad, what I said on the forum was a little difficult. Could you give me more details, such as what commands to use and how to operate them? Thank you! In addition, never let me reinstall it, OK?
The following figure shows the disk capacity I checked using the df command:
File System capacity used available % mount point
/Dev/sda6 20G 14G 5.6G 71%/
Udev 2.0G 348 K 2.0G 1%/dev
/Dev/sda7 435G 86G 328G 21%/home
/Dev/sda2 2.1G 4.0 K 2.1G 1%/windows/C