replacing storm windows broken plastic clips

I have storm windows (Macon brand) and screens that slide up and down by pulling inward on plastic devices which appear to be spring loaded. The plastic devices lock into slots on the window frame to prevent the window from dropping down. When you pull inward on the device, the plastic devices pull away from the slots on the window frame, allowing the window to be moved up or down.

The plastic devices slide horizontally on a track in the window that is 1/2" wide. The plastic device is 3 7/8" long. At the end of the plastic device, the "notch" is 1/4" wide and is formed to a 45

i think that part 91-054 will work for me. Question: how do you remove the old part to make sure?

Is there a video demonstrating the procedure?

Thank you, Charles