My first time with a burn barrel , I have a barrel but need to remove the top and add holes for good ventilation . Any tips on cutting the top off and adding the holes ? Do you drill the holes or punch them ? What do you punch them with ? And what about cutting out a hole or rectangle in the bottom and add a screen of some sort for ashes to fall through ? I am planning on raising the barrel on a few bricks for additional air flow at the bottom .