Replacing the trigger valve on a nail gun is a very simple process that only takes about 15 minutes. OK so the first time I took it out it took me a half hour but then I took two extra roll pins out that I did not need to.
In the package you get the new valve, instructions (I found confusing), grease for the O rings, and a punch to drive out the roll pins.
Here is a picture of the old valve "green" and the new valve "white". You will notice they have changed slightly. The new style go's in without a problem. Hopefully it is more durable that the old style.
Reference the picture, you only need to remove two roll pins. One is for the trigger and the other is for the trigger valve assembly.
Once you remove both roll pins, you must pry out the valve assembly, you can easily do this with a screwdriver. There is a pry point to locate your screwdriver.
Once you get the old valve out you simply install the new valve. Make sure you apply grease to the O rings and make sure the slot is lined up so the roll pin can go in.
All that needs to be done now is reinstall the roll pins. The trigger one was a little tricky to get lined up. Use the punch on one side as you start the roll pin on the opposite side.
The job is now complete and you have saved yourself about a $100 bucks.
I paid about $35 for the replacement valve including shipping. I only checked a few sites, one had it for less but was out of stock. I chose not to wait and paid the extra $7 so I could get it right away. If I did not need it right away I may have chosen to wait.