Replacing Battery on Uwatec Galileo and Scubapro Square

[Manuel Sam]

I am trying to replace the batteries on my Uwatec Galileo Terra and my Scubapro Square dive computers. Both have the same style battery compartment covers that have a coin-size slot with two holes on either side. I've opened them and replaced the batteries before, but this time, they are virtually frozen. I've tried every coin available in my arsenal - US coins and foreign coins - that are about the width of the slot. The only thing I have "succeeded" in doing is to gall the edges of the slot; in essence, I have gradually reduced the coin gripping surfaces, so to speak, making it even harder to turn.

Does anyone know of a commercially available tool that was made for this and which engages both the slot and the two holes?

Thanks,

Manuel