If you want to do maintenance for your MuZ ETZ 251 then it is always a good plan to have access to a Workshop Manual to keep just for a guide just in case you need to know how to remove a certain part for example Gearbox and install it again accurately.
MuZ ETZ 251 Workshop Manuals will give you special diagnostic guides for your car so if something is broken it helps you work out what the problem is and easy methods to correct it. After that you can assess if this can be achieved by yourself or in case the job is simply too big you can actually book your ETZ 251 into a local car garage.
MuZ ETZ 251 manual