I had never done it till this time around but I found it a simple enough task.
There's only 2 standard sizings for the mounts (between centres)
The rotors are NOT round, so you slip a suitably sized zip-tie between the peak of the rotor and the back of the throat of the disk caliper put another zip tie on the actuating arm of the caliper to lock it on in place.
Mark where the holes need to be....job done?

At least, it was for me.