OK, thanks for the tips.
Is there a video for how to change the touch screen + digitizer (not only the digitizer) or its the same as the digitizer change, without the separation of the lcd and digitizer?
Its pretty much the same.
You take the screen an digitizer off the mainboard as one part. If you have a bundle just replace both at once.
Here are some good videos:
http://www.youtube.com/watch?feature=player_embedded&v=cL-jnUKufC4
I think you dont have to disassemble all these parts.
Generally you loosen the 4 screws, take out the mainboard with all parts,
dissconnect the cable from buttons and display and use a wire/flat tool to disconnect the screen from the cage where everything is glued on with double side tape.
then you reconnect cables from new screen, press it on the cage in perfect position with fresh tape, click cage in housing, 4 screws and done.
in the video you can skip 1:30-1:40,
loosen the mainboard screws
skip 1:45 -2:55
loosen the button connector
Skip then untill 4.44 thats the display connector.
If you skipped everything you cant lay it like in the video. But if you remove the display as shown later in the video there is a small gap that allows you to remove this cable.
You save much time by doing it this way. also i found it hard the first time to remove all parts, especially the rigid-flex board as its glued and never will fit perfectly again ;D
Its maby a bit trick to release the display cable and reconnect it between the gap but i would try.
ANOTHER HINT:
There are small glass parts that connect the sensors for light / proximity with the glass..
Dont loose them ;D