I absolutely love these fireplace doors!  I have to say I was a little concerned about installation, but my concerns were unfounded.  I did it alone.  It was easy, did not require drilling, though I would advise watching the video they provide a link for.  
One more thing if, like me, you find a lot of soot build up on the face of your masonry when you remove the old set of doors-believe it or not, a paste of cream of tartar mixed with water, painted on and allowed to sit for 5-10 minutes before being rinsed off, really does work!