Replacing a toilet seat

I've bought the new seat and started removing the old one but can only get one of the bolts off - the other one is stuck. I need someone who can finish removing the old seat and install the new one. The old toilet seat came with the house when I bought it but I think it's a Legacy(?) - the hardware looks similar to this one: https://www.mitre10.co.nz/shop/legacy-toilet-seat-white/p/399655 but there doesn't seem to be any way to lift the hinge up to get to the screw underneath.