In this guide, I’ll remove the Asus N550JK back cover, refer to this guide, you can upgrade RAM, SSD and hard drive for your Asus N550JK.
The Asus N550JK comes with a 4GB DDR3L 1600MHz RAM, and also has a spare ram slots.
The Asus N550JK has no spare mSATA port, if you want to add SSD, you need to remove the hard drive and replace it by 2.5″ SSD.
You can remove the optical drive and install the hard drive to the optical drive bay.
RAM: provide two ram slots.
RAM Type: DDR3L 1600MHz.
SSD: replace the hard drive with a 2.5″ SSD.
Second HDD: support, but you need to buy a 2ND HDD caddy and remove the optical drive.