Repairing a broken chain
Ever had to quit a ride because the chain broke? No? Well, you’re lucky then, because when you’re in the mountains or in a deserted place somewhere upcountry you can’t hike back to known territory within reasonable time and hoping someone will find you and give you a ride back is also not preferable…
So here is a compact description of how to repair a broken chain:
First of all you need a chain tool, this is a tool that by screwing a piece of metal through the chain you push the chain apart. see the picture on the left.
just pick a link in the chain, apply the tool and twist it until the pin from the chain link is almost pushed out of the chain.
The first few twists need some force, and you’ll probably hear a snap, once you heard the snap the rest is easy going.
Once the chain is opened, you can twist it a little and separate the links.
Remember, that when you do a quick repair because its broken you have to remove a pair of links of the chain, cause its hard to fit two outer links together 
see picture above for detail.
For a more visual detail:
Good luck!