I'll give you two options and you can choose one to try.
On the Extreme that you want to use to extend the network, power it up for a few minutes and then hold in the reset button firmly on the device for 10 seconds and release. Allow a full minute for the Extreme to restart to a slow, blinking amber light.
On the iPad....
Tap Settings on the home screen
Tap WiFi
Look for a listing of Setup a New AirPort Base Station
Tap on AirPort Extreme
Follow the prompts
All that you really need to do is enter a device name for the Extreme. AirPort Utility will take care of the rest.
On the Mac....
Open Macintosh HD > Applications > Utilities > AirPort Utility
Click on Other WiFi Devices
Click on AirPort Extreme
Follow the prompts
All that you really need to do is enter a device name for the Extreme. AirPort Utility will take care of the rest. No "setup guide" is needed.