Help Roca Toilet Seat?

Can someone help - I have a roca bathroom seat that has fallen apart at the hinges. The seat is off, but I cant figure out how to put a new seat on ? There are 2 plastic things sticking out. which are plastic. I cant seem to screw them off or pull them off.

Also B&Q only seem to sell standard seats, and this toilet does not have screws at the bottom so not even sure what I do when I get a toilet seat ?

Thanks