From the article: Apple has now added parts and tools for all M4 Macs to its self-service repair store in the U.S. and many European countries. This includes parts for MacBook Pro, iMac, and Mac mini models with M4, M4 Pro, and M4 Max chips.
Since its launch in 2022, Apple’s self-service repair program has given customers access to the same genuine Apple parts, tools, and manuals that are used by the Genius Bar at Apple Stores and Apple Authorized Service Providers, enabling DIY repairs. Manuals for repairing M4 Macs are available on Apple’s website.
Depending on the model, parts available for M4 Macs include displays, logic boards, speakers, trackpads, top cases with a keyboard and battery, SSD modules, USB-C ports, fans, Wi-Fi antennas, and more.