From what I've been able to ascertain, it's just not a _thing_ unless you want to roll-your-own migration tool. There's a few-years-old issue that's now closed:

From what I've been able to ascertain, it's just not a _thing_ unless you want to roll-your-own migration tool. There's a few-years-old issue that's now closed: https://github.com/tootsuite/mastodon/issues/177 https://github.com/tootsuite/mastodon/issues/177 but links to this currently open issue, which mostly reiterates that this is problematic for a number of reasons: https://github.com/tootsuite/mastodon/issues/12423 https://github.com/tootsuite/mastodon/issues/12423 From what I understand, it's fairly trivial to post to _multiple_ ActivityPub accounts, but true _migration_ just doesn't exist per se.