265/5 CR doglegWhat Getrag 265 do you have - 265/5 (dogleg) or 265/6 (overdrive)?
Thank You.https://www.wallothnesch.com/en/gas...535i-m535i-you-need-1-for-1-car-23-00-00.html
If you are not a mechanic - maybe it is better to give it to gearbox specialized shop.
But if you want to try - that might be helpful:
http://www.bimmers.com/m3/troubleshooting/BMW M3 Factory Manual/23-manual_transmission.pdf