I really can't tell from your picture what it looks like, but I'll take your word for it that it's pushed in a bit.
Do not try to pull it back out with tweezers. It won't work and you could short the battery, or damage it another way.
Here's a diagram of how batteries are made. That is for a protected cell, but they are all the same on the positive end.
Under that positive end cap there is the PTC and pressure valve. If you damage those at the least you've lost a lot of battery protection for when things go wrong. I would not mess with that area of the battery. I would recycle it and consider it a lesson learned.