I looked everywhere for how to install a bulk head on a rain barrel that has an attached lid that cannot be removed, but could not find any solutions.
This is what I did.
I found this flexible electrical conduit in my shed.
It has 1 fitting at each end. I removed one fitting and left one to be be used as stopper for the bulk head.
I dropped the other end of the flexible conduit with the bulk head into the barrel. Then pulled on it from the bottom all the way until the threaded part of the bulk head came out of the whole.
I then maintained pressure on the conduit until I got the bulk head secured tight with the supplied nut.
(I lost the last pic that shows it all nice and tight).
I hope this will come in handy for some one.