Extractor R&R (in 30 seconds or less)
Manonsteyr, the plunger you were pushing on is the latch for the access cover on the rear of the slide.
Extractor R&R:
Note: Definitely do both the disassembly and reassembly in some sort of container; one slip at the wrong time can send the plunger and spring flying.
Disassembly:
a) Insert small, flat-bladed screwdriver between extractor plunger and extractor.
b) Twist screwdriver 90 degrees, thereby simultaneously compressing plunger past retention ledge on extractor stud and tipping extractor forwards. If the screwdriver you've chosen is on the small side you may have to pry a bit while it is turned the 90 degrees. The extractor should now be tipped forwards out of its normal position with the plunger caught on the major diameter of the extractor stud. You should be able to pull out the screwdriver without disturbing the extractor and plunger from that position.
c) Invert slide and push on the bottom of the ejector stud with the srewdriver through the access hole in the underside of the slide. This will send the extractor, plunger and spring flying, hopefully to be caught within the box or bag you're doing this in.
Reassembly:
a) Put the plunger in the spring.
b) Insert the spring and plunger into their hole with the small bevel on the plunger outwards. The large beveled surface, which pushes on the extractor, should be inwards.
c) Lastly, use the rear surface of the extractor's stud to compress the plunger & spring, when the extactor gets to the rear of its channel you press inwards on it and it snaps into its place. This does require a fair amount of finger pressure, and you may slip once or twice before you get the hang of it, so once again it's good to have a container surrounding the slide in case the plunger and spring take flight.
Do the job a few times and you'll find it to be quite easy. My second time through took less than a minute. The last couple of times have taken about 30 seconds.