How to remove a ruger mark pistol barrel?

Lol. YouTube. Watch it twice before you attempt it. Do it in a bin so you don’t loose anything, and so it’s easy to take it to a smith when you can’t get it back together. They suck to work on. I have five of them.
I know how to take the gun apart and put it back together as I collect mark 2’s but the reciever barrel portion is what I am talking about. I want to separate the barrel from upper reciever and add a longer barrel more than 10” that they sell. I will then add a hangiard and a butt stock. For a survival carbine like the beretta neos 22 carbine kit
 
The one time I took a MKII off it was extremely tight and had lots of thread locker on it. Boogered up the barrel and twisted the receiver. Barrel was trash anyway and managed to straighten receiver but won't do it again and wouldn't recommend doing it unless you have the proper tools/knowledge (which I don't).