First of all....Welcome to the campfire.
It depends upon your skill level and the tools you have available to you.
The video shows work which was perportedly done with Dremel moto tool.
I have used Dremels for a long time and have found that they are very good for intricate work but I am not able to use mine to do the work that was done on that pistol.
I am not disputing the video. And I am not saying it can't be done because there are plenty of folks out there who can do it.
That leaves you with some careful work with a file, or clamp it into a milling machine. I have enough skill with a Dremel to smooth it up as finish work.
Once you are finished with the metal modifications, you still have to touch up the bluing.
The revolver in the video appears to have been done very well.
I am not a converter kind of guy because I can't rationalize the economics. If I had one I would try it myself but my skill is too low to try it with a Dremel. It would be milling machine and I would proceed very cautiously.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson