Originally Posted by
Stratmando
I got your Email, Wanted to attach the Image here, forget how, it will let you attach a URL, Want to attach a photo? Anyway
Turn Power off, remove the Left Single pole switch, you could identify that red wire with yellow tape, this is the switched leg, connect this red(yellow tape) to the common of this 3 way, red and black will connect to the 2 traveller screws.
Then the Black that went to the Left single pole switch will connect to the white that goes downstairs(identify with black tape on both ends), this white with black tape will connect to the common of the downstairs 3 way, and the red and black connect to the same colored dark screws(traveller screws).
In this case the Hot end is downstairs and the Switched end is Upstairs.
Turn power on, test lights.
Good Luck