It's very easy.
Do you have the Wireless network set up?
Can your computer join the wireless network?
Now is the PLC connected to the wired network that the wireless is wired to?
Do the subnets match?
Do all devices on the network have unique IP addresses?
Once you answer yes to all the above, it's simple. We then use RSLinx to define an Ethernet/IP driver, & browse to the device.