First UDS build

Finally got my hands on a free Craigslist 55 gallon barrel. I have done a little research on building a UDS barrel smoker but now that I have my barre, I am realizing that a sealed barrel is a little more complicated to deal with. I have tools and am confident I can remove the lid, however, I like the look of the flat top lid as opposed to the Weber dome style lid that seems to be much more popular on sealed barrels.

Does anybody have any experience on using a flat lid on a sealed barrel drum? How did you go about saving the top and creating an air tight seal? I can go back and get another barrel to cut another lid off but I don't know if that will help. Any suggestions would be appreciated, thanks!

I have an angle grinder, chisels, basic hand tools, sawzall. I work in the trades so if I don't have a tool I probably work with somebody that does and have access to using it.

Yellowhair, how do you create an air tight seal grinding off at that spot?

Alright sounds good. So it sounds like I grind through the lid but I don't go through the barrel. I should be able to handle that.

One more question; is there any trouble keeping condensation from the flat lid from dripping onto meat? Any suggestions to divert it away?

10-4. Thanks for the help all, I will post pictures throughout the process