O.K. I have successfully opened up my Teclast C260. I thought, since I won't be doing this too often (I hope), I would take a few photos:
http://rapidshare.com/files/43094726/C260A.jpg.html http://rapidshare.com/files/43094990/C260B.jpg.html
I am now able to reset the device into firmware upgrade mode - thanks to Tbear for giving me the information and confidence to do this.
I must admit though, there are now visible scratches on device, at least its no longer a brick!
I am now facing the difficulties of trying the new firmware.
The newest version that works for me is 01.07.1240
After translating the newer firmware docs, it seems there is some patch procedure I need to understand for newer firmware to work.
I am trying things out now.