When you connect, you would telnet into your default gateway. The password will be the console password from the AP system profile.
You would then be able to see the environment variables by typing:
bootenv -j
You would set any environment variable on the AP by typing:
bootenv -p name=value
e.g.
bootenv -p master=192.168.1.3
You can also erase parameters:
bootenv -p master=
bootenv -s will factory default the AP
reboot will reboot the AP