TomatoUSB

I am trying to install Tomato on a stock t-mobile cellspot router which I understand is a ASUS RT-AC68U
Here is what I have done:

Downloaded: tomato-RT-AC68U-ARM—129-AIO-64K.trx
Downloaded: TR-N66U Firmware Restoration

Disabled firewall and antivirus
Tried loading fimware using both dynamic and static ip settings to 192.168.1.10 (and 192.168.1.2):
Sometimes it loaded and then sayed something like "Restoring router configuration" but then reboots to stock firmware

I tried using tftp in both windows and linux. This failed to connect when using 192.168.1.1 or dynamic IP settings. When using static settings of 192.168.29.10 and loading it to 192.168.29.1, the file actually uploaded but the router rebooted only to stock firmware. Same results when using the tftp2.exe utility. I have also tried going to the ASUS firmware first (RT-AC68U_3.0.0.4_378_4585-g44c234f) with no luck.

Any other ideas?

Watch this video. I was able to put TomatoUSB on mine by watching this.

I cant post the Youtube link since I am a low karma user, but go to Youtube and search for this "T-Mobile Router (Asus RT68U AC1900) Changing Firmware". The video was created by a user called "TerpSkins316"