in your settings page is an export button, which lets you download your subscriptions and block list, which you can then import into a new Lemmy account on a new instance.
You just make an account on another instance. I think there is a way you can migrate sub/block lists and such but I didn't bother so I couldn't tell you how.
That'll be pretty useless if most of their communities are lemmy.world communities, it's not a good idea to divorce an instance but still participate and be dependent on their communities, unless you're willing to obfuscate your activity with alts that aren't connected to you. Otherwise they'll just ban you from those communities anyway.
Also be warned, it doesn't take your post history, or even saved posts with you, if you want saved posts you have to bring them manually, and you can't take post history with you at all.
Also be warned, it doesn’t take your post history, or even saved posts with you, if you want saved posts you have to bring them manually, and you can’t take post history with you at all
Probably not a big deal for the majority of people. Just link your old profile in your bio if you want to keep your "reputation"
Saved posts will probably be a bigger deal since people saved them for a reason.
Also I did mention bringing history with you because spiteful admins can wash your history away when you can't bring it with you. If you could claim and reassigned ownership of the federated posts and comments they'd only be able to wash it away from the communities they moderate.
I'm not sure, I know that on this account I have over 100. On Lemmy.world I probably have way more. I have 40 on pawb.social. I have a lot here though. Much less on the others since I use those accounts less but I still have a handful on all the others.
Reputation can just be "recognized". I remember probably between 25 and 50 usernames here, most of them for good reasons, it's good to be able to recognize them even if they move instances