I haven't remapped anything in about 10 years and I did the e30 about 15 years ago but... the bin file is on eprom or eeprom. You have to remove that chip and replace it with something that has your custom information on it. Moates (i'm not sure if they still exist) was big into Ford Mustang programming. One of their products was an eprom emulator that took a usb cable. You would go online and get a bin dump for your model and a definition file for the same. The definition file separated the 1's and 0's into maps that could be changed. You could then write your new bin to the emulator and plug the emulator into the socket where you removed the eprom from. You could then make changes on the fly if you kept a laptop in the car.

There may be better ways now, but I doubt it on an e53.