Hi,

What is the hardware version of the MR6400? 

May I know why do you want to change another antenna? 

First, we do not suggest you to change antenna,cause the antennas on one device work alternately, while if you want to change the external antennas on your router/AP to meet your special Wi-Fi requirements, we recommend you to replace all of them with same type of antenna other than change only one of them.

https://www.tp-link.com/en/home-networking/3g-4g-router/tl-mr6400/#specifications

May it help and have a nice day. 

Yunan wrote

How to remove antenna for TP LINK MR6400 ? becouse i want to change with another antenna

 

Thanks