I was frustrated by the videos on Youtube showing different ways of soldering a BNC connector but none explained in detail. Sometimes you even needed special tools to do it.
Here you can find BNC connectors and all the tools you need to finish your job:
1. BNC connectors: http://amzn.to/2BE4TcA
2. Soldering iron: http://amzn.to/2BFMk7R
3. Soldering tin: http://amzn.to/2EVoRSe