Does anyone have any tips on opening these? Do I have to stick something in the two holes at top. I do not want to break it.

With most of the carts, you can just snap them open and closed without breaking them. There are little tabs on the inside of the cartridge.

I've found the best way (so far) is to use a driver to unlatch one of the right or left sides 1st, via the dig/pop method. Usually after one of the left or right side latches are open it's easy to open the rest.

However some games have the middle peg that can have an adhesive, so you have to twist it a little, those games are a bitch.