Any suggestions for safely discharging? I have two very old puffed up phone batteries, both removed from their devices, but I can't figure out how to discharge

Any suggestions for safely discharging? I have two very old puffed up phone batteries, both removed from their devices, but I can't figure out how to discharge them since they won't fit in their devices anymore and I don't have any background in safely handling stored electricity. I've looked for advice online, but it mostly requires tools I don't have, or sounds like someone completely made it up and it isn't safe at all.