I recommend not doing it yourself.
most folks will send their gun out to get worked on. I believe freestate does it here in MD, there are a few other forum members that have mentioned it in the past.
favorite of all time is http://www.boresightsolutions.com/
I remember when he was small potatoes.
Ahhhhh, you modded a Gen 2????I was going to try my soldering iron, but instead had Engage (IP on this site) do my Gen 2 G21. Very satisfied.
http://shop.engagearmament.com/index.php/about-magento-demo-store
Ahhhhh, you modded a Gen 2????