Friends Laptop (backlight dying?)

Yesterday my buddy asked me to take a look at his laptop because he said he could faintly see the things on the screen, to a point that they were near complete black. Anyways I started it up and I noticed that the first screen was a little pinkish, but then colors became vivid and looked normal...it started up and I logged in and looked at his desktop to see nothing appeared to be wrong. I walked away for like 30 minutes and came back and noticed it was black. I proceeded to restart the computer and it was bright for about 5 seconds, and went black, I could still see the Windows screen though by getting a nice angle.

I've never really dealt with laptop problems before so I wanted to ask here. My first intuition tells me the backlight is on the verge of being completely dead, but something is allowing it to hold out for a little while. A little reading tells me that it's also possible for the backlight inverter to die as well, and that it's more common?

Would the symptoms (working for a little while then dying out) be able to pinpoint which one it actually is?

Side note, his computer is a 3 year old Dell, I want to say D600 but I'm not right next to it so don't quote me.

And just so I don't have to reply later on, what's the difficulty scale of replacing these things, I don't want to make him take it somewhere and have them charging him an arm and a leg. I've built desktop computers in the past and tried to read up on how to do it...looks like the backlight would require some soldering (which he is confident he can do).

Thanks in advance to anyone that replies.