The bottom cover of the MSI GS66 Stealth laptop features many small holes, primarily designed for heat dissipation. The bottom cover is made of metal, which maintains the structural stability while achieving a slim design.
To remove the bottom cover, we need to unscrew all the screws holding it in place. It is worth noting that one of the screws is covered by MSI’s fragile sticker. If the fragile sticker is damaged, you will lose your warranty. Therefore, it is not recommended to upgrade the memory and SSD yourself during the laptop’s warranty period.

After removing the bottom cover, let’s take a look at the MSI GS66’s internal structure. Its cooling system includes three fans and seven copper heat pipes, which keep the laptop stable under heavy load and help prevent overheating. The memory modules and SSD are covered with black thermal pads, effectively enhancing cooling efficiency.

The laptop has two memory slots and comes with two 8GB 3200 MHz DDR4 memory modules. You can replace them with two 16GB 3200 MHz DDR4 memory modules if necessary.

This laptop comes with a 1TB Samsung PM981a SSD, which supports the NVMe protocol.

This is the AX201NGW wireless network card, which supports Wi-Fi 6 and can achieve a maximum wireless transmission speed of 2400 Mbps over a 1200 MHz bandwidth. In addition, it has an M.2 port on the right side that supports the PCIe standard and can be used to install an M.2 SSD.

It comes with a 6,578 mAh (99.9Wh) lithium-ion battery pack. Its battery capacity is considered the highest among slim laptops, almost 1.5 times that of a typical slim gaming laptop.

“So, during the laptop warranty period, it is not recommended that you upgrade the memory and SSD yourself.”
Can someone at Best Buy do this for me without voiding the warranty?
Your best bet is to contact MSI by email and ask them how you should go about the upgrade. It might take a couple of days, but they’re very nice to communicate with. The machine has to be registered in your name with them, so if you haven’t already done so, do that first.
I say they’re very nice because they issued me a one-year warranty on a non-functional MSI GE62VR laptop that I completely rebuilt using parts (motherboard and screen) that I bought on eBay. I sure didn’t expect that. Take Care.