Guardian Storm Door broken sliding window latches

by Vince
(London, Ontario, Canada)

I have a Guardian storm door with a sliding window in the middle of it (the serial/model number may be in one of the attached photos). Both latches on either side of the sliding window have broken and I was wondering if you would know where I could get the part and if so what are the part numbers and if you could add a quick "how to..." with your response.