Gordon,
The link described a situation where a user couldn't boot his machine. The Rescue CD/Live CD gives you a way to get in, but when you do that, the file system on your hard drive isn't mounted, so you have to mount it. Then root permission is required to change the /tmp and /var/tmp folders.
Specifically to your case, with root permission, just do this step for the link:
Clear out both directories (i.e. 'cd /tmp' then 'rm -rf *' etc.)
Caution: I recommend you be sure you know what you are doing when using the 'rm' command.
Then make the change as described in the link,
Once booted into desktop, launch YaST's "/etc/sysconfig Editor"
Drill down to 'System' -> 'Cron' -> 'TMP_DIRS_TO_CLEAR'
Add to settings: "/tmp /var/tmp" (no quotes)
Then go to 'System' -> 'Cron' -> 'CLEAR_TMP_DIRS_AT_BOOTUP'
Set to "yes" (no quotes)
This problem will not recur.
Good luck!