[CN [G22 RTF2]]

I recently had Trijicon night sights put on my G22 and today I went to the range and put about 150 rounds through it. When I got home and took the barrel off to clean it, I noticed that the front sight had come loose, but I don't have a tool small enough to tighten the bolt.
I could bring it back in but Id rather save myself the drive.
What's the best way to fix this?
Any advice would be much appreciated.
-Chris