First you must remember to remain calm, noobs tend to attack on their own and they are weak on their own.
If you come across a group of noobs your best bet is to run.
If you decide to take on a noob you will need to get out your best flame thrower. Noobs are vulnerable to flame throwers because they are highly flamable bree of troll that dines on spam.
Also, don't get one of those cheap flame throwers. You may be thinking "It's all just flame!" But it's not. Certain types of flames are more effective against noobs.
If you use the flame thrower well enough the noob should surrender and you could then report it to animal control and they would take it away.

Remember, stay calm.