Create the new account you want to move to if you didn't already. It doesn't have to be a new account.
Log in to the account you want to move TO and go to Settings > Account > Moving from a different account.
There enter the handle (@profilename@instance.whatever) of the account you want to move FROM.
Now login with the account you want to move FROM and go to Settings > Account > Move to a different account.
There enter the handle and password of the account you want to move TO and hit “Move Followers”.
In the old profile, go to "Import and Export > Export" to download your follows, lists, bookmarks and further information as a file, if you want to move this data too. The files can be imported via "Import and Export > Import" in the new profile.
Go to the account you moved TO again and import the file with your follows.
Wait for the follows and followers to be moved and you're done.