Changing the Cellular (LTE) chip on the iPhone

Hello, in my country, LTE is only on band 7 (2600 mhz), which isn't supported by the iPhone 5.

What I know is that the iPhone has native support for LTE, so it CAN recognize LTE chips, it's not like trying to add an LTE chip to the iPhone 4S.

What I wanted to know is if I could replace the current cellular chip for another one, from some phone that supports band 7 LTE, like Motorola Razr HD, Samsung S3, S4, HTC One, etc.

I read that the chip is part of or glued to the motherboard or logic board or something, so technically it would be impossible to replace it, but I couldn't know for sure... Maybe I could replace the entire logic board...? I don't know, I'm really a dummie when it comes to hardware. Of course, I would get help of somebody specialized/professional. Does anybody have any idea on what I could do?