Ok I got in my pipe. I had the metal yard pre-cut it for me so it's faster.

Here is the pipe and tabs all ready.


Here's a pic of my plans.


Here I have marked where I'm going to cut out material from the pipe using a plasma cutter. There is an identical mark on the opposite side.


I try to use something straight as a guide for the plasma torch anywhere possible. Here I'm using a copper bar held on with a clamp.


Both holes are cut out.


Here I have cut out a hole for the drain port.