HI,
If you have little knowledge on WLAN config, it is very simple. it is completely wizard oriented config.
Step 1 : reset it to the factory settings, you will find a small hole back side of the IAP. Power up IAP and press the button for 30 sec and remove the power while continue pressing the button, as a good practice repeat this for two times.
Step 2 : Now uplink it to a POE Switch and allow it get a valid IP
Step 3 : After boot up it will broadcast "Instant " SSID, connect your laptop to Instant SSID.
Step 4 : Open browser and it will take you to the web UI of IAP or if you know the IP you can web UI over the wired network.
Step 5 : Now select new WLAN and wizard will be opened to configure the new WLAN.
If you are very new to configure WLAN please go through the videos available online or go through the User guide.