The GL-E750 Mudi is an LTE router. It's particularly interesting because of built-in featues like VPN and Tor support.

And with blue-merle there exists an extension to change the routers IMEI number, which allows to re-use the router for providing anonymous internet.

1. Update the Mudi to latest firmware, at least 3.215.
2. Get SSH console access to the Mudi. See upstream docs for details. It might be that you have to change your local SSH config for this to work. See the linked tutorial for details.
3. Update opkg package list:

   opkg update

4. Download blue-merle installation package from Github:

   curl -LO https://github.com/srlabs/blue-merle/releases/download/v1.0/blue-merle_1.0.0-1_mips_24kc.ipk

5. Install blue-merle:

   opkg install blue-merle*.ipk

6. If the installation stops with “Your MCU version has not been verified to work with blue-merle.”
   1. Answer the question “Would you like to update your MCU?” with “y” and wait until the Mudi is shutdown.
   2. Restart the Mudi.
   3. Repeat the steps “Update opkg package list” and “Install blue-merle” from above.

1. Login to your Mudi webinterface (http://192.168.8.1/) and see the current IMEI.
2. Login to your Mudi via SSH.
3. Start blue-merle:

   blue-merle

4. Follow the instructions. It's particularly important to change your location in between the SIM & IMEI change to protect against correlation matching.
5. Again login to your Mudi webinterface (http://192.168.8.1/) and see the changed IMEI.