W114 Automatic K4C025 A1142701201 Occasion lock switch extend

Hello community, have already read some info to me and so only unfortunately with the topic of occasion lock switches everyone seems to shy away or so, what is the problem with the thing? Ok, my problem of the car can not start any more, neither on P nor on N. Recently he jumped again, after a long time back and forth from P to R again. Now no more, think it is definitely what kaput in or at the occasion lock switches. Just how do I build this thing out? Does this have to be the whole gearbox out? Can someone please help me? Thanks in advance and greeting