How to root Galaxy S3 with android 5.1.1?

Hi all. I've installed cyanogenmod 12 and now I've android 5.1.1 on my GS3 i-9300, but the question is: how can I root?

I've no more the root permission, but all the guide that I've found online explain how to root Galaxy S3 with android 4 ore less, not L. Can you help me? Or I can't root?