I just e-mailed a friend a reply to the same question. I'll post it just in case it helps...
The screw in the top of the trigger is the sear (striker) adjustment. With the frame upside down, (hammer not cocked) adjust the screw clockwise till you hear a click. This is the striker releasing. Turn the screw back out 1/2 turn from that point, and this is close to optimum sear engagement. Turn the screw counterclockwise and it will increase the sear engagement making the trigger pull longer and seem heavier. If it isn't heavy enough, or doesn't feel consistant, the striker or trigger could be worn, and I'd send it back to TC.
If you feel competent to work on it, pull out the owners manual and:
1: Remove the grip
2: With the frame upside down, remove the trigger guard stop screw, making note of how the spring sits in the frame.
3: Drive out the trigger guard pivot pin, and the assembly pulls out of the bottom of the frame.
4: Cup your hand over the top of the assembly, and push out the trigger pivot pin. Be careful, cause the spring and the spring cup may launch when you pull out your punch.
5: Pull the trigger backwards out of the housing, and it will hopefully release the spring and cup into your hand and not across the room. You can then replace the light spring with a factory spring and reinstall everything in reverse order. If a factory spring is not available, you can stretch the existing spring till you can get a factory spring, but the stretched spring will fatigue faster than a new spring. Always have a gunsmith check your work!
