How do you get the door to open. I have waved the two handed sword about for hours but can not open the door Help Me please!

I had a lot of problems with this too i even began to wonder if it was glitched but eventually by sheer luck rather than management i managed to get the final one open, I am sorry it does not help you as i cannot explain how.

You use the sword to open the door obviously.

Horizontal red cracks are unlocked using a horizontal swing, verical cracks using a vertical swing. Get in line with a crack and use the sword as needed and its energy effect will do the rest. About six or seven pinpoint swings and you've got it.

It does not work. How far do you stand from door where do you place your target cross. The power strike is the only one to give off energy. both red cracks are horizontal above the door a little gap between them

You've got to position yourself so the power attack energy effect strikes the line. Standing just far enough back from the door so that it's in your field of view is good, I did mine on 3rd person. I was probably standing 8 to 10 feet back from the door. The strikes have to be precise and try to center the crack in your field of view if in 1st person. It's doable though not always easy. Play around and experiment fo a bit and you'll get it.

You have to aim at the red lines with the cross (it took me a while to figure out), and make sure you move your sword in the right direction - ordinary or sideway power attack.

If you are playing on console, use the the left stick to determine the direction that the ray travels.

EDIT: Ninja'd