Cool Change Two Way Switch To Single
Make sure to connect the earth wires even if the switches are plastic so there is an earth present throughout the length of the new cable this also ensures there is an earth to connect to should the switches be changed for steel or brass in the future.
Change two way switch to single. Replace the original one way switch for a two way switch connect the wires as shown ensuring you tighten up the terminal screws fully. Clearly power to both switches comes from the same circuit. To replace two switches with one simply eliminate one switch from the power circuit and connect both outgoing wires one is red one is black in your photo to the same switch.