[Galaxy Tab 2 Q&A, Help & Troubleshooting] graphdarnell:
My Tab 2 7 had a swirling crack on the digitizer (touchscreen). Looked for a tutorial on how to replace it in vain. Saw the teardown at Tech Republic, but that's it. No mention anywhere that I could find about how to do it. Decided to bite the bullet and ventured to fit a new one. Successful. Wrote down a quick guide thinking it might help someone since I saw a bunch of tabs with smashed digitizers on Ebay. Some claim it's gorilla glass, which makes me kind of wonder why they shatter so readily. I know, gorilla glass only scratch-resistant, but still...

Samsung sticks the digitizer to the bezel-frame with a tough double-sided tape, similar to the kind Asus uses on its tabs. A tutorial for the Tab 2 10 shows the use of a putty knife to scrape the digitizer off its frame, which wouldn't work with the 7, as its bezel-frame almost totally covers the edge of the glass back side. On the other hand, inserting anything metal in between from the front would scuff it badly.

The LCD display was taped to the magnesium frame, but is separate from the touchscreen, which need not be removed when replacing the digitizer.

What you need to do is to follow the steps in the teardown referred to above. As Tech Republic correctly pointed out, the internal layout is quite neat, unlike some of the tabs I've had the chance to disassemble. There are many thin cables, however, and you need to proceed with patience.

You must remove all components, so that only the frame with the digitizer and LCD is left. Eventually, you'd have to employ some source of heat, be it a heat gun, a hair dryer or a heat lamp to soften or to some extent melt the adhesive of the digitizer. Leaving any electronic component in place and the heat might destroy it. You can use brute force to separate the digitizer from the frame, but you'd more likely than not damage the LCD in the process.

What I did was use a heat gun at ~500 F, held at about 1 to 2 inches from the edge of the digitizer, and went back and forth over it, one side at a time, for no more than 30 to 35 seconds. I used a blunt object to push the glass out at spots plainly visible as illustrated in the attached thumbs below, then slid a plastic tool with a flared end to pry it from the bezel along its edge. Be careful how you handle the frame, since it would get burning hot at this point. As I moved from one side to another, I wedged a guitar pick between the glass and the frame to prevent them from sticking back together. You might pulverize parts of the glass as you go along, but in general it flexes quite a bit and wouldn't shatter.

Once you get it out, you need to remove the residual tape on the frame. The digitizer I bought was lined with new tape so I didn't have use any extra adhesive. It doesn't bind as strongly as the original tape, but enough to hold everything in place.

Putting it back is just the reverse. I took the extra step of reassembling the whole thing first with just the digitizer hanging loose, plugged it in, turned the tab on to make sure it functioned correctly before bonding it to the frame.

Basically, the process is nothing new. However, just the fact that someone has done it might give confidence to other DIYers in the future. Feel free to ask if any questions.

http://www.techrepublic.com/photos/cracking-open-the-samsung-galaxy-tab-2-70/6360139?