Want to change my netwrok mask

Network with 2 subnet: 192.168.10.0,192.168.0.0
Have one PDC:192.168.10.4
one BDC:192.168.10.8,192.168.0.8

Now I want to change these two subnet into a bigger one with the netmask: 255.255.254.0

should I reinstall these two Domain controllers,or is there anything I should pay attention to?

Any assistance is appreciated.