I normally use a small jewelers screwdriver. The flat blade pushes the barb down and allows it to slide out pretty easily.
Make sure you are pushing the screwdriver into the gap at the back of the connector, between the metal connector and the plastic housing (not between the connectors where the card would insert).
If you look on the diagram on the BR link, that little flap of metal is what you need to bend down so it will slide out of the housing.
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