How to setup 2 AXs in ethernet series from an AT&T DSL modem

I want to expand my exisitng ethernet network (AT&T DSL modem -> Ethernet Cat6 -> AX -> WiFi). My home is concrete block ranch, so one AX doesn't cover the whole house.

I am running the latest version of ML on a 1TB, 16GB RAM, MBP 9.1 (non-retina display). Maximum hardware running off Wi-Fi is: 2 MBPs, 1 PC, 3 iPads, 4 iPhones. All hardware is running latest updates.

I wired the house with Cat6 ethernet with 4 RJ-45 LAN access jacks.

The proposed new configuration is:

ATT 2010-02 DSL Modem -> Ethernet Cat6 -> AX1 -> 5-port gigabit switch --> Ethernet1 Cat6 -> AX2 -> WiFi

|

|-> Ethernet2 Cat6 -> TV Internet connection

|

|-> Ethernet3 Cat6 -> open LAN connection (for PC, etc)

|

|-> Ethernet4 Cat6 -> open LAN connection (for PC, etc)

|

|-> Ethernet5 Cat6 -> MBP 9.1

Where:

AX1 = Airport Express MC414LL/A, model A1392, simultaneous dual-band 802.11n WiFi

AX2 = Airport Express MB321LL/A, model A1264

I assume both AXs are setup in "bridge mode" & "Create a new network", but I don't know where to go from their. I have read several posts, but it is not clear what to do when the AXs are different generations and connected serially. One AX setup I tried turned the Internet light on the modem red. I had to reset the modem and router to get back to square one. Where do i go next?