I wanted to upgrade the wifi card of my laptop. Only thing is that Lenovo has a whitelist of acceptable cards. You can patch this out, or go further and install coreboot, an open-source bios thing. Basically, I followed this guide. I used a bus pirate, and I had to do the wake on lan method of powering the top chip. Basically, plug it in and plug in an active ethernet cable. I also broke off some of the SMD components near the top bios chip. I had to look up the schematics for the x230 and find 0402 components that were close enough.
I replaced R1378 with a ~72 ohm 0402 resistor by hand. Leaded solder paste made it easy. Originally it was a 33 ohm, so 72 is close enough. C748 is used for a voltage sense line. Probably not actually needed, but whatever. I think it was supposed to be a 50V 2200 pF 0402 cap. I replaced it with a 1000pF rather badly. No issues! I did need to reinstall grub to the actual hard drive. Previously it was a UEFI boot, which I don't know if coreboot supports. Have yet to try windows.