Xiaomi WiFi Router 3G (switch+wifi only configuration)

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi guys,
I need to configure this device only for switch and wifi. (no need firewall,dhcp..)
I already have a main router and I want all devices in the same ip range assigned by the main router.
for example..

main router 192.168.1.1
xiaomi router 192.168.1.2
devices connected to the main router or xiaomi router 192.168.1.3 - 192.168.1.x

In the end...I no need the wlan port of the xiaomi router
I just want a lan to lan connectiont and use the second lan port of the xiaomi for a wired devices.

How to proceed?
thanks in advance
https://openwrt.org/toh/hwdata/xiaomi/xiaomi_miwifi_3g

2
  1. Give the lan interface on the xiaomi a static adress 192.168.1.2
  2. Disable the dhcp-server on the xiaomi lan interface.
  3. Maybe you can make a bridge between the lan-vlan and the wan-vlan and in that way have 3 lan-ports. I am not sure about that possibility.