Keypad Confusion

[twpot]

Hello everyone, I'm not sure if there's something I missed in the instructions and I'll admit I'm new to a lot of this stuff. I'm at a crossroads to how to put the keypad together. it came with a pin header that looks like it needs soldered in and I was just looking to see how everyone else has done it before I go crazy and screw something up by putting it through the wrong connectors.

Thank you for any help and advice, it's greatly appreciated! :)