Siromer 244e Gearbox problem

[Cl1ff]

Hi, Iam a new member with a problem. I purchased my 2012 Siromer 244e with a gearbox that was stuck in reverse, thinking it might be a selector problem I removed the top of the gearbox to find broken teeth on one of the gears and a twisted and bent main shaft. I have now split the tractor between the creeper and the main gearbox, question ? can I make all the repairs from here or do I need to remove the lifting mechanism to get behind the gearbox, and are these parts available
Thanks for any advice
Cliff