Hello I have a community with a few servers here, currently tracking without any problem, but the person who had the account is not anymore an admin.

Is there a way to change he's account to this one without loose the tracking system and position we have in our servers.

Yes, you're more than welcome to claim the servers in the exact same manner as if no one had claimed the server. What errors are you running into?

My question is, do i get a trouble if someone already claimed it before?, because the person who claimed it, is not an admin anymore.

Can i reclaim it, because this person was using he's personal account?

No, you would not get in trouble for claiming your own server.