S7-400 redundant seperate

Helloo. everyone. i want ask something about s7-400 redundant mode THAT
Our industry got s7-400 redundant PLCs(2 plc works by redundant).

i suppose to seperate 1 plc and to cancel redundant mode from our redundant system. so i want to our plc works by standart (1 plc works as indepedently)
then i dont know what hardware & software trouble will happen?
what should i do?

If your PLC pair is working correctly, then you should be able to take one away and still have it function correctly.

However, depending on how it was implemented, there may be a large amount of reconfiguration required to make all the red error lights go away.

yeap
1. Firstly disconnect optic cable between 2 plc
2. seperate ET module's probi cable
3. then change hardware configuration on software.
any other things need?