login as root? how?

[Tech2k]

I must change a file to let my scanner work in Knoppix.

But when I want to save this file , I don't have write permissions. I only can do that as "root".

I already created a password for "Root" , but how can I login as root?

Well I gurss you know about su and sudo on knoppix live cd to go from $ to #.You say you created the passwd already if so then to login type :
#login root <then passwd when asked>
#login user <then passwd when asked>
$su <passwd when asked>
$login <name and passwd when asked>
#login <name and passwd when asked>

Get the idea?