How do u take down a lvl 2 wall?

[Hydrogen]

I just started, and the highest lvl wall seems to b lvl 2. It's pretty annoying, since I can't attack them in fear of losing my knights. How many rams do u need to take down a lvl 2 wall? And does it stay down after the rams, or only for 1 attack?

[Wrecking]

Once the wall is down its down. They will have to rebuild it. And send a scout to see how much units they have.

[Asplundh]

It takes three Lvl-1 Rams to reduce a Lvl-2 Wall to Lvl-1.