moved the Peanuts specials exclusively to the streaming service Apple TV+.
However, the Halloween classic will be available to watch for free, without a subscription, on the Apple TV+ app or website for three days: Friday, October 30 to Sunday, November 1, 2020.
Watching it via the Apple TV+ app definitely isn't as simple or universally accessible as a television broadcast - the length of the explanation in this post is proof of that - but it's the only free option on offer this year, if you don't already own the show on home video.
To watch, you'll need to either install the Apple TV+ app on a supported device; or watch it via a web browser, on any computer, at tv.apple.com .
Supported devices include: Apple devices including the iPad, iPhone, Apple TV set-top boxes, and Macs; Roku or Amazon Fire TV streaming devices; and select smart TVs from Samsung, LG, Vizio, or Sony. For more information about supported devices and setting Apple TV+ up on them, see this Apple support webpage.
You do not need to subscribe (or even start a free trial) to Apple TV+ in order to install the app on any of those devices and watch It's the Great Pumpkin, Charlie Brown during the free period. However, you will have to sign in with a new or existing account Apple account (such as the one you use for iTunes, Apple Music, or iCloud). But signing in does not subscribe you to Apple TV+.
Once you're in the Apple TV+ app, the show is featured on the front page of the app, or can be found in the "Kids" section. At the tv.apple.com website, for the moment it's listed at the very top, but if you don't see it there, you may need to scroll quite a ways through the list of shows to find it.
See Apple's website for more information about the AppleTV+ streaming service in general.