Make sure you have everything crucial backed up and saved before progressing. Back up the machine with an external Time Machine drive.Create a bootable USB macOS Catalina disk.Once you have your parts in hand, here are the steps I followed to upgrade my systems to the latest version of macOS 10.15 ‘Catalina’ with new SSDs. The Sintech NVMe M.2 adapter is considered to be the best and you can get them directly from Amazon. I used the Adata XPG SX8200 Pro 512GB 3D NAND NVMe Gen3x4 PCIe M.2 2280 Solid State Drive, but would consider the Sabrent 512GB Rocket NVMe PCIe M.2 2280 Internal SSD. Larger drives (1TB) appear to be a bit faster, I didn’t see much need to go beyond 512 gigabytes of storage and wanted to keep it relatively inexpensive.

If you have a 15” Macbook Pro you may benefit from a faster SSD because of the PCIe 3.0 x4, but the rest of the models are limited by PCIe 2.0 x4 giving them a theoretical limit around 2,000 MB/second (results from the thread rarely get above 1500 MB/s with 13” models. There are a lot of options for which SSD to purchase, the general consensus from the MacRumors thread was that the Sabrent Rocket and Adata XPG SX8200 models provide the best price/performance results.

Heat resistant Kapton/Tesa/Sellotape insulation tape.

Isopryl alcohol for cleaning the aluminum laptop case.

Compressed air for cleaning out dust from the laptop’s internals.

I bought a Smart Phone Repair Kit here in Australia, you may want something similar from Amazon.

P5 Pentalobe and T5 Torx screwdrivers.

The iFixit Mac Laptop Repair guides provide excellent step by step instructions for SSD replacements specific to each model. Make sure you have the right equipment for performing the upgrade. These are the 2 machines I updated, named for Futurama characters. has thorough descriptions of each model, use About This Mac-> System Report to gather up all the details of your system. Take the time to figure out exactly which model you have before getting starting. The total cost was under $90 USD each for upgrading to 500 gigagbyte drives. Go read at least the first page of that thread if you have questions I don’t answer, there are 220 pages of feedback so far. There is an amazingly thorough thread on this, but I figured I’d post my experiences upgrading 2 of my laptops that I’ve upgraded so far. Relatively recently (10.13) it became possible to upgrade these systems with an aftermarket adapter and stock NVMe M.2 form factor SSDs. The SSDs used by MacBook Air and MacBook Pros shipped between 2013-2017 used a proprietary adapter. Apple laptops are somewhat notoriously resistant to upgrades.

Late model 2015 macbook air ssd upgrade