Just a quickie...

Anyone needing to change RT 622 trailer lock cylinders just follow the 2 (or more) videos on YouTube. When you get to the part where you are actually removing the cylinder, insert your current (wrong) key all the way and then push down on the little tang on the back side to release the old cylinder. Push it out (VERY gently) as far as it will go. Now, slowly pull your key out while still GENTLY pushing on the cylinder. The concept is this: You do not have to have all the pins retracted at once. So long as your key has at least one set of cuts for each pin length in the cylinder, you can get the old cylinder right out easily. As each "caught" pin is retracted, the cylinder will slide out further and further until it is out. You will no doubt have to work the key out and back in a few times to get the cylinder all the way out. IF you happen to not have one of a needed cut depth, you could try a small screw driver. "Picking" one pin is not too hard. (at least not as hard as picking them ALL at once!)

I just did mine this way. I also had taken the whole lock and handle assembly out of the trailer "just in case". Had the above "trick" not worked, I was just steps from the drill press. If you must drill this thing, USE A VICE! The bits WILL grab the edges inside the cylinder and could cause you PAIN and/or a broken mechanism. ...and start with a small size drill and SLOWLY work your way up until the whole thing comes out. Run the drill fast and push into the cylinder VERY SLOWLY. You MAY still need to depress the hold-in tab at the back of the cylinder after you destroy all the pins.

Also, be prepared that the screws shown in the videos in the latch assembly may be different in reality than shown on the video. I had 2 Phillips and 2 T-10 screws holding the moving part of the lock. I little grease on this part at applicable places wouldn't hurt on re-assembly.
Good Luck,

Mike