The Saltwater etch process

Step 24 Crystal socket

Then you cut their tails off and insert them into the holes and solder. You have a compact socket, with the PCB itself being part of the assembly.

I have a closeup of the crystal mounting so that you can see the details.

It is possible to grind away some of the rear end of those pins in order to reduce height. The part which actually makes contact is the spring inserted inside the hollow pin, and you can grind away quite a lot of material without damage to the internal working parts of the pin sockets.