My whipped cream can has run out of nitrous. I want what's inside anyway. What's the least destructive method of doing so?
Circular saw will fill it with metal filings - not great for the mouthfeel, I'd think.
Pliers aren't sharp enough to puncture.
Can opener will have no lip to grab.
Your first issue will be the container skidding out of your control - with potential for finger-loss &amp; furniture damage. You're not going to easily find any implement you can squeeze slowly to make the first cut, you're going to have to hit it with something sharp.
Your second will be how much gas is actually left in the container &amp; what that results in.
Messy but possible, grip it in a vice &amp; puncture with a hammer &amp; fine wood chisel. Then use something like aluminium sheet cutters (they're like big, tough scissors) to finish cutting around the perimeter.
Cons:-

Spray/spatter on your first puncture, assuming you can hit it hard enough to penetrate the top face without going straight through &amp; pouring the rest on the floor.
Sanitising the tools.

I'd just bin it.