Because of their mushroomed pins, using a master link on KMC K1 and K1SL chains is highly recommended over pushing the pins out and back in (which can damage both the pins and side plates, creating a weak spot).

If that's your chain of choice, pick up a few spares. Missing Links are good to have around and can be reused.

To install and remove, use Park Tool MLP-1.2 chain link pliers.