How to remove a nikon d3100 memory stick if its facing the other way?

I inserted the memory stick in the camera but i noticed it was the wrong way how am i suppose to take it out

If its like most other devices that i've used and it won't eject itself or anything like that, you just have to try getting it out with your fingernails or tweezers or some other small tool

If it's backwards, use some tweezers and gently pull. If it's upside down, be very careful of the gold leads. Still try some tweezers but be very gentle.
I can't imagine how you put the card in wrong without some force?

You can pull it out, but when you do, be aware, your card slot is probably useless from that point on, and if it uses those cards for video storage, toss the camera and get anew one.