A:
The RAM on this unit is not considered to be a user upgradable item by Lenovo, since it requires a partial disassembly of the computer to access the module.
That being said, it is a standard DDR3L SODIMM, so if you are reasonably skilled at working on laptops, you should have no trouble swapping out the 4GB module for an 8GB.
Be aware, though, that this will likely void your warranty.
Aloha, TRP (Lenovo partner service tech)