On Skyrim's Mainquest is a part named "Gain entrance to Sky Haven Temple". I have tried to complete it but I'm not able to do so. The problem is big stonehead which seems to be a door to the temple. I have tried to open it several hours, but can't do so. It's probably connected with those five carved stone tablets on the floor, but without any clues I'm not able to figure it out. And I wonder why Esbern stands still near of the cave's entrance sword in his hand and it is not possible to talk to him. What I'm needed to do to get through that ****** stonehead-door?

How to do that? The circle is not able to activate and I tried to kill Delphine on the circle to open the door - it didn't work in that way. so how to sacrifice blood?