TP-LINK WR1043ND v4 WAN port change

I have install LEDE 17.01.4, and i'm trying to change WAN port, because the original is dead.
I have 2 working lan ports (3,4(1,2 are dead)).
Can anyone give me some solution?

P.S. I'm trying to change it from: Network->Interfaces->WAN-edit, but nothing.

I have search for same topic, but haven't find. If have delete my and sorry.

look at the switch part and change the vlan id 2 untagged to another port or add another vlan id untagged port
this is a 2 wan example

after that go into physical option and add it to your wan


I think the 1043 has two CPU ports and a 7 port switch (the two CPU ports + the 5 Ethernet ports).

Default switch configuration is for two VLANs one untagged on each CPU port, one is LAN and one is WAN. You don't need to change that. Just move one of the good Ethernet ports to be untagged on the WAN and turn it off from the LAN. Turn all the bad ports off in all VLANs to avoid confusion.