S7 1200 change IP address

I have a S7 1200 CPU on which I set the IP address using primary set up tool. Now I want to change the IP of the CPU. It wont allow me to change through primary set up tool. If I change it in the TIA hardware configuration then I would not be able to go online. Is there another way to change the IP? Help appreciated.

solved

I had to reset the cpu to factory settings. It's under online diagnosis then functions. It's all good now.

Even if you change the IP address in TIA hardware you should still be able to go online. It won't find it on the first attempt but there is a tickbox to let it find all CPUs regardless of IP address.

Thanks, will try that tomorrow.