Welcome. I don't know many people who feel like changing a transmission from automatic to manual, or manual to automatic, or anything like that worth while, seeing as so many other components have to be swapped as well, but I don't know what work might go into that swap. Post up some pics when you can, its nice to have another 5-Series owner on the forum.
Hmm. You will have to replace the transmission, the transmission control unit, get the clutch pedal out, replace the steering wheel if you are wanting the paddle shifters, and replace the shifter and probably the mechanical parts underneath, and possibly replace the ECU and the cluster. If it is something you want to do and have the time and money to do then go for it, but be sure you do some in-depth research as to how long it will take and how much all of the parts required for the swap will cost to make sure you don't get half way into it and realize it is more than you were willing to get into. Good luck.
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