I'm sure you could, but it's gonna be a ton of part hunting, and work. I'm fairly certain the motherboard is proprietary, and not easily replaceable. You're gonna have to rip everything out, either find a MOBO that fits, or alter the case to make one fit, use a small form factor PSU and GPU, and a small cooler. It'll be a lot of work, but anything can be done if you're willing to work at it.