@FerunSorry for addressing yo in english. I hope after all these years you are still willing to answer. I found this post after a long search and I'm not speaking polish. Could you explain in more detail how exactly you were able to open the gear box? It needs to turn? I am able to get some movement in the lid. But there is no space appearing between the lid and the casing. Did you have to use a lot of force. How exactly did you do it? Thanks a lot for you time and explanation.