Unlocking 4G Bands

I have an A500F that I bought in Bahrain (United Arab Emirates ROM). I’m now back in the United States and using the phone on my carrier here. The problem I have is that it is not connecting to the 4G signal for my carrier. The 4G signal for the Bahrain carrier operated on the 1800 MHz, and my carrier now operates on the 1900 MHz and 1700/2100 MHz bands. I wish to enable those bands on my phone. I know it is possible with the S5 (http://forum.xda-developers.com/gala...ds-to-t2886059), but I can’t seem to get the Windows software to cooperate with my A5. Not sure if I need a specific Ark Kernel, or if I need to install a custom ROM.

I would prefer not to flash the entire ROM. My phone is rooted, but I’m still using the stock Kitkat ROM, and I’m quite pleased with it.

If anyone can help, I would be in your debt.