I just cracked my screen in several places. Is there a way to replace?

Yes! You can replace it. I’ll worn you it won’t be cheap ;-{

Here’s the guide you’ll need to follow to take it off Remplacement de l'écran de l'iMac Intel 27" EMC 2546

You’ll also need this kit [produit lié absent ou désactivé : IF174-005] and I recommend getting two sets of these Plastic Cards

Here’s one source for the display iMac 27" LCD Display Panel & Front Glass Assembly (12/13)

Before you start… Use packing tape and cover the entire glass surface with it to hold the together as when you pry on the display in the process of taking it out glass shards can pop out with some force! Also wear safety glasses.