Replacement toilet seat

[AlwaysReadyForABlether]

Ok this has to win the award for the most boring thread ever!
I broke the bathroom toilet seat yesterday so went and bought a new one today confident that I could fit it myself.
But when I went to take the old one off I realised that the screws don't go right through the pan and come out underneath as you would expect. I can't get the old fittings off completely so I'm not entirely sure how they're held on but there is just the chrome part on the top of the pan and nothing underneath.
Stupidly I had opened the new one before realising this so now can't take it back.
But does anyone know how I replace what I've got?