Use a zip tie, or anything flat and roughly the size of the spade connector, to slide into the slot as you slide the spade connector out of the slot.

Make sure the zip tie holds the spring contact down before you remove the spade connector.

Your new motor may come with power cables already installed. If so, repeat the last three steps with the new motor to remove its power cables.

Leave the zip ties in the new motor until you're ready to plug in the spade connectors.