Installation of the extractor is fairly simple.
Get a small pocket size screwdriver and use a stone to lightly round off all sharp edges and corners.
Test fit the extractor in the bolt by slipping it back/down into place. It should fit and move freely.
Inspect the tunnel in the bolt for debris, burrs, or rust, etc. I've found rust, grit, factory metal shavings, etc in new bolts, used bolts can be full of god knows what.
Lube up the spring and plunger and drop them in the hole.
Use the screwdriver to pull the plunger and spring into the bolt tunnel as you slip the extractor back/down into place.
Allow the plunger to seat against the back of the extractor.
Check the extractor for free movement and good spring tension.