How to disassemble a Skoda Octavia DUU Gearbox

Hello!

Is there anyone here with the knoweledge on how to disassemble the DUU gearbox found in for example the Skoda Octavia 1999-2001?

I need to remove the bell housing in order to change the weak rivets for nuts and bolts but there is something catching the housing.

Even though all the bolts have been removed i can only lift it by about 2-3mm (1/10 inch) by using a rubber mallet. This has never happened with any previous gearboxes. And the skoda "techs" only know how to remove the box not how to open it :confused:.

Any ideas?

Thanks in advance

Sincerely

///Henrik (The swede)