Agree that its pressed on, per the parts diagrams in for some of the replacement parts: https://cobratransmission.com/BMW-NV...er-Case?page=2

Heat makes sense to me, maybe with a 3 jaw puller if there's enough room for a bite. Or after halves apart and just front side of case still capturing the shaft, tap on shaft and see if it drives out of the cover (maybe with some heat too)