THE WEDGE IS OUT! I'm like a master gunsmith now
It was very easy. I was doing it all wrong yesterday, because I concentrated on pushing the wedge spring downwards. I thought that I have te keep that spring down, otherwise the wedge won't be able to move. That's why I thought I need 3 hands, as I wrote a few posts above. That's why I wasn't able to hit it properly, because all the time I was trying to keep the spring pressed down, while at the same time holding the piece of wood on the wedge WITH THE SAME HAND, while hitting (not hard) that piece of wood with plastic mallet in the other hand.
Then Jim The Saviour wrote to me prophetic words of wisdom: "The lip will move down if the wedge moves to the left. Just hit the darned wedge,
hard !"
And that was the solution and the whole philosophy of the whole wedge thing -
ignore the spring and
hit hard! THANKS JIM!
With several very hard blows using the plastic mallet (mine has a head which is larger than on the average plastic mallet), the wedge was out without a problem. In that process I destroyed two pieces of wood which I prepared weeks ago for this purpose. So the wood is not ideal for this, too soft, I'll need something harder.
I will probably order today what you recommended or something similar:
https://www.trackofthewolf.com/Categories/PartDetail.aspx/1041/1/TOOL-KEY-B
But I am afraid that this will leave some marks. If I see scratches, I'll go back to wood. If I have to destroy a piece of wood every time, so what?
The lip of the spring caused a tiny damage at the spot where it was forcefully pushed inside when the mallet-blow pushed the wedge. But I guess that was unavoidable, and the damage is really tiny.
It was even more easy to reassamble it. I pushed the wedge back inside with a thumb, but for the last tiny bit (for a lip of the spring to pop-up again on the right side) I gave it a smack with a mallet on the left side and that was it - back in its place again and everything very firm as it was.
I popped a few more caps today, this time with SILICONE rings ("keepers") on them (I tried VINYL ones before). I had sparks normally this time. Milky silicone keepers turned black, but they were undamaged, can be reused. Unlike vinyl tube, keepers from silicone tube don't cause any difficulties when caps with silicone keepers on them are being put on or pulled off nipples. Because they're twice thinner. All spent caps retained their form, with just a small crack on top. It's very easy, fast and smooth to take them off nipples with a tweezers - just catch with tweezers that small protruding piece of the cracked top of the cap.