1 - 3 horas
The screen backlight on my 2007 black MacBook would go out whenever I opened it past a certain angle. I didn't want to spend hundreds on having the Apple Store work on a 5 year old machine, I don't have the funds for a current upgrade, and I wasn't going to stoop so low as to buy a Windows machine. So, I decided to try the fix myself. I searched the Web and discovered two possible culprits: the inverter cable, and the inverter. So I bought both.
The repair went quite smoothly. It took about 3 hours to take apart and put back together, but that was because it was my first hardware repair in years, and my first laptop repair ever. The only step I would have called "difficult" was reinserting the screw securing the optical drive (Step 20), since the data cables kept getting in the way and knocking the screw out of place. Otherwise, it was a simple matter of following directions carefully and meticulously.
Make sure you are keeping track of which screws go where as you disassemble. I accomplished this by printing the instructions, laying double-sided tape on the pictures, and sticking the screws, as they came out, head down onto the picture that represented the corresponding step.
Also, get a second pair of hands to help you hold the data cables out of place when you are trying to reinsert the optical drive screw.
And a magnetic head screwdriver is a gift from the Gods.