Open Menu > More Applications > Terminals > Konsole.
Type su then press Enter. When you are prompted for a password, just hit Enter again.
Your indicator will change from the dollar symbol ($) to the hash sign (#). It should also be indicated that the user is root.
[root@localhost ~] # passwd
When you are prompted to enter your old passwd, just hit Enter. When prompted to enter a New Password, type in a darn good one ... at least 8 alphanumeric combination that would include at least a capital letter and a symbol. But you must be able to remember it. When done, press Enter. You will be asked to re-enter the same sequenced combination, do so then press Enter again. You're set.