Agreeing with all the good advice already given! Below are some possibly helpful links.
That dark pin is the master pin in the CCS's KMC K99 128 link chain. I broke my CCS chain with a chain tool the other day, to take it off the frame and solvent wash it to remove the gunky factory lube that gets all pasty with the aluminum paint-like coating of the chain. It really picks up road grit.
Well, I pushed the master pin back home carefully, but that dark pin is somewhat riveted, mushroomed a bit: that's how the factory makes that special pin stay in place. The joint required a little bit of English on the chain tool to get the joint working freely again. I did not get it working
perfectly freely, it was binding just a little, but it is OK enough.
Sidebar. I have long since settled on
Finish Line "Dry" lube: PTFE solids and a very light synthetic oil in a hexane solvent carrier. I apply the stuff regularly and wipe the chain down frequently. I mention this sort of lube, of the many classes available, because its oil is so very thin and light that it grabs and holds less road grit; it does not make a thick pasted gunk collection of mud. And the worst of the dirt that does accumulate can be washed off with soap and water very easy and the "dry" lube reapplied. Upon re-application, the stuff (like any other liquid chain lube) will displace water and some dirt from the internal moving surfaces of the chain. Your chain will always blacken a clean rag, however. That's the nature of chain wear: the polished off micro particles of steel always look gray or black on a rag. The same principle as polishing metal, the rag darkens.
I found a video where the fellow explains a flex-fix technique on a Shimano chain similar to what we have on the CCS bikes
Here is
a suitable master link to replace the master pin system. This is the common sort of master link and it is reusable.
It's easier to deal a master link with the
Park version 1.2 pliers that both open and close the link.
The chain being the bike's lifeline, it is empowering to have the few simple tools needed to make the chain work, or replace it, or take it down for cleaning, etc. Here is
Park's mini chain breaker. You might find it a few dollars cheaper if you shop around....