I need help with wiring this switch

[Sberry5]

That looks like singles is it tubed into that cavity box.

It is

 

[Sberry5]

In that case it's a one way switch, and would need replacing by the 2 way equivalent.
Once that's done, the wires that are currently in COM(mon) move to L2, and you connect your 2nd switch in parallel - COM to COM, L1 to L1, and L2 to L2.

Thank you very much Brian appreciate your help

 

[goasis]

How many wires are currently in that 1 way switch? It looks like only 1, in l1, is there anything in common?

 

[davesparks]

How many wires are currently in that 1 way switch? It looks like only 1, in l1, is there anything in common?

Yes, the common of each switch has 2 wires in it, the link between them and an incoming/outgoing feed.

 

[goasis]

Yes, the common of each switch has 2 wires in it, the link between them and an incoming/outgoing feed.

Fair enough, it just looks like the cable looping round to me but that might just be the angle of the photo