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Is disabling the radios on the antenna enough to replace the existing 3 of the 2.4 Ghz antenna with a different model?
Not sure if I need to shutdown the power by unplugging the POE cable from Power Injector and RESET the button to also stop the battery power.
Cisco's radios and antennae are field replaceable. You can just replacement even when the radios are enabled or the AP's are still powered up.
If you don't want to power down your AP, shutting down the radios is another option. It's alot faster.