My router, supplied by my service provider is feeding a CPE710 on my house which is set on AP mode.  It's bridged with another CPE710 in client mode on a pole, about 500 feet away next to my boathouse. The COE710 client is plugged inside my boathouse.  The outside WiFi signal is excellent and the speed is too.

Unfortunately the WiFi signal will not penetrate the walls of the boathouse.  I therefore want to connect another access point inside my boathouse using the LAN port on my CPE710 Client's power block. Can this be done, and how?

If not, can I use an outdoor wireless range extender to feed off of the CPE710's wireless signal and broadcast through the walls of my boathouse. If yes, what is the best hardware? 

I also have a TP-Link EAP225-OUTDOOR. Can I use this device to create the indoor AP in my boathouse by connecting both the LAN ports of the POE adapters and configuring it as an AP?

The little pictures on the TP-LINK site shows this configuration, but I can't find any instructions on how to do it.  

Help please.