The toilet seat in our 'new' house needs to be changed but the toilet bowl is the newer type where the toilet bowl is part of a solid block where the bolts holding the seat on are not visible underneath (hard to explain what I mean here). On older toilets you could access the bolt underneath at the back but on this one the bolt is within the block. Does that mean I will have to unbolt the toilet bowl from the wall to get access to the seat bolts?
Hard to say without a picture, but you should be able to slide a cover off and access a little screw from above. It shouldn't be necessary to remove a toilet to replace the seat.