Is it theoretically possible to upgrade the RAM?

It's a question that's been bugging me for a while.

Is it possible to - after finding a similar enough RAM chip as whatever's already soldered on the board - remove the chip from the mainboard and solder on a chip of higher capacity?

From a bit of research, the Tegra X1 chip supports up to 4GB of RAM maximum. The Shield TV has 3GB of RAM, so if I found a 4GB chip and had someone replace the 3GB one, would it work? I mean unless there's some weirdness where the system reserves some RAM and just reports 3GB or something.