On step 29, when you flip the LCD screen over, I strongly suggest covering the LCD with any kind of clean cloth. If you flip the screen like shown, the remainings of the adhesive on the frame will stick to the LCD and you will have to carefully clean it later. I also advise to cover the LCD entirely whenever touching it either for flipping over, or when you remove it entirely from the iPad. Or maybe work with it wearing gloves. I had adhesive residue and lot of fingerprints on LCD, quite hard to clean. Although I tried to be careful, sadly in the end I could notice some small scratches on the LCD.
Exactly, the title offers the access to the sensor to clean it, yet we only get the instructions to replace the entire zoom lens which comes with the sensor assembled. There are no further steps on how to disassemble the lens unit to get to the sensor itself. By the way, the article refers to the sensor as "CCD", however this camera uses BSI-CMOS sensor (not CCD, which is a different technology).