how do I solder a wire to this so that I can use a microcontorller to trigger it via outputs?
I would say get glasses first !
What is "this" - is it expecting TTL level voltages?
I can't see what it is but , if a wire already goes into it you can splice. If its just a board location you can sand it lightly add a little solder - shape and tip a jumper then solder it right onto the board.
my robots my garden