BMW used to manufacture a kit for the e38 and e39 to do this conversion. I would assume it would transfer over to the e53 as well. I built my own kit using the schematics that bmw provided using parts I got from digikey and mouser to install the high cluster in my e39 touring, it wasnt too difficult. I do remember having to buy a new dash buzzer, as the one in the car didnt have all of the correct connections to do this conversion. I built the kit so that it would be reversable, dont ask me why I did, I dont know. I cannot recall if a coolant temp sensor had to be bought or if the sensor in the vehicle was there but you had to install a wire in the connector where one wasnt present or not. Do a search online for "e39 low to high cluster conversion" and the schematics should pop up, they actually give you a step by step procedure on how its done. Paul "fixels" is a great resource as well, but he spends most of his time on the Bimmerforurms in the e39 forum. I can tell you that the Oil Gauge and Tach lights will not work with the m52/4.