Ready????............Do not remove the lid. Use a center punch to punch two holes in lid on each side.
Not to big......just enough to get the paint out. Once you have enough poured out, screw in wood screws or sheet metal screws. I've been using the same can for three years.
If you are doing a full frame........forget what I just wrote.
Also the instructions state NOT to shake. I shake the can each time I use it. I pour the paint thru a coned paint filter. Works perfect. Filters can be purchased at the paint store. For me, the regular Por-15 is to shiny. When it has set for about an hour I throw a fog coat Rustoleum semi (color of choice) over Por-15. Go light as Por-15 needs to "gas off". Let set for 24 hours minimum.