I have converted from 1 way to 2 way before, but i can't understand the wiring in my new house. i have at present 1 way 2 gang switch with 3 twin and earth coming down the wall. All of the blue wires are in a connecting block, one of the browns go to the l1 of the left switch another goes to the L2 of the same switch and the final brown goes to the L2 of the right switch. I have then got another single piece of brown piggy backing from L2 on the left switch to L1 on the right switch, which one is the switch wire and how do i convert to 2 way switching ?