EGR / AGR OFF
Normally for egr off you only need to write solution in ecus flash and thats done. sometimes you may need to, depending of ecu allso remove the connector to egr valve. Older engines with vacuumoperated valve, just unplug valve vacuumline and plug it.
DPF OFF
Start by writing in the original unmodified file. Then use proper diagtool of your choice to reset dpf values to 0. Now that values have been reseted to zero, replace with downpipe / or delete the dpf system from exhaust. Write the solution in and now your done. ps. on some rare cases you may need to remove the temperature and pressure connectors from dpf system.
ADBLUE/SCR OFF
Start allways on original file, again use the diagtool that can RESET the adblue unit. For reset meaning no error codes and no dashwarnings. After your done with reset, now time to pukll out ecu and write solution in. In newer ecus like md1 youre required allso to unplug the adblue unit/module after solution written in. Sometimes there are separate module for it, sometimes its included in adbluetank module.
NOX OFF
Normally just an reset on noxsensor values on original file and disconnecting sensor is enough after writing modfile in.
DECAT
Just write solution in, problem sorted
ps. remember that laws in your country may prohibit roaduse and these solutions are meant for raceuse only on closed tracks.