root password hacking is fun! This is one of my favourite questions to ask in interviews for Linux people. Going along with deadalus.globalnode's comment, we'll assume this is your computer where you do have access to try these things. These methods are fairly advanced, but I'll try to give as much detail as possible.
First thing you need is a linux live distro. Any suse install or live disk should work. Assuming it's a suse disk, boot off the iso and go into "Rescue Mode". There should be a menu option when the cd boots.
One you get a root prompt: you have 2 options:
1. chroot into your system and run the password command
The first thing we had to do is identify your root partition:
fdisk -l 2> /dev/null | grep dev | grep -v dm
Every system is different, so if you can post the output we can probably determine which filesystem is your root.
Once we know the root file system:
mount /dev/$root_file_system /mnt
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
mount --bind /dev /mnt/dev
Some of the above commands may be a little overkill for a password reset, but it's good to do anyway, for future reference.
At this point you should be able to type the command: `password`. It should ask you for a new password. Type it in twice and should take effect.
Again the above commands are a safe but paranoid way of rebooting. If you just reboot without doing the commands you will probably be OK.
2. Edit the shadow file with a known good password hash.
Thinking about it, this is actually even more advanced, so we'll leave this as a last resort if option 1 doesn't work