I have a 2018 model X with FSD. It's current HW is 2.5.
I heard some people got the message from Tesla for HW3 upgrade, but I didn't get any message yet.
Do I need to make an appointment for the upgrade?
I think you can set up an appointment using the Service option in the Tesla app. Many months ago, before I had the upgrade done on my Model 3, there was an option there for scheduling an upgrade. I'm not sure it's still there currently for owners with HW 2.5, but you can always choose "Other" and type in your request.
While no Tesla vehicles are fully autonomous today and require active driver supervision, the FSD computer is capable of delivering intelligent performance and control to enable a new level of safety and autonomy, without impacting cost or range. Learn more about FSD computer installation.
That support page suggests "'Schedule Service’ > ‘Accessories' > ‘Upgrades & Installations’ and add ‘FSD Computer Upgrade' in the description"
I received my HW3 upgrade with my MCU1 AP2.5 EAP to MCU2 package a few months ago and a few phantom brakes are gone. I guess you will receive the HW3 upgrade only if you purchase FSD (or if available the subscription + additional $1,500 fee for the HW3 upgrade).
Schedule the update in the app. Don't be surprised if your appointment gets deferred while parts are shipped to the SC. Ours was deferred by one week, and unsurprisingly I was getting a lot of emails from FedEx/Tesla that suggested that the parts still hadn't arrived. Nonetheless, the mobile service arrived as expected and did the upgrade in our garage. Took about an hour, though plan on the car being unusable for 1-3 hours after while the software is reloaded into the FSD HW. You'll need some period of time while the AP cameras recalibrate before AP is available, though I think it took only a few miles for my wife to get the features back.