I hate drug "one uppers" that think they have both experienced and understand everything. It's almost as if they think the only valid answer is "yes, I have experienced that" and then proceed to describe a completely unrelated experience.
It doesn't matter if you've done ten times more varieties of drugs ten times more than I have. That doesn't mean your use of vocabulary is more accurate than mine and it certainly doesn't mean that you've experienced every possible drug experience. Why is everyone so ashamed to be humble when it comes to drugs?
That being said, "ego death" actually means something in psychology and no one here seems to be using it properly. It is a complete failure of both short and long-term memory. It is not amnesia. You can remember the experience itself. However, during the episode you fail to remember even the most basic of concepts.
You don't know that you're on a drug. You don't know what drugs are. You don't know what humanity is. You don't know what you are. You don't know what life is. It is just raw subjective experience with no analysis whatsoever.
If you're doing ketamine alone in your bedroom, for example, and achieve ego death you won't even understand that there are other people in the world or even that there is a world on the other side of your door.
The most interesting aspect of the experience for me is "coming back online" when individual concepts are restored in a particular order. You might have a sense of having responsibility to "be somewhere at some time or else people will get upset with you," but not understanding why and then only after some time later remember that you have a job and have work the next morning.
As for how to achieve it, I would recommend ketamine. Start with a small to moderate dose and work your way up to be safe.