Here's the official guide from Microsoft to replace SSD in Surface Laptop 3

Microsoft really wants large enterprises to adopt Surface devices. Serviceability is one of the main reasons Surface was not adopted by the large enterprise customers. Microsoft is fixing this issue with the new Surface Laptop 3 and Surface Pro X. For the first time in the Surface lineup, these new Surface devices come with removable SSDs. Microsoft has now published an official guide for Surface device disassembly and SSD removal for technicians and IT professionals. Microsoft has mentioned the following tools and components that are required for SSD removal.

• Tools:
  • Torx-plus 5 screwdriver (5IP)
  • Anti-static wrist strap (1 MOhm resistance)
  • ESD safe battery cover (13.5” or 15”)
• Components:
  • New 3IP screw
  • rSSD (If replacing)

You can download it here from Microsoft.

PSA: If you are a general consumer, you may lose the product warranty if you remove the SSD on your own.

via: WalkingCat