How to transfer ownership of an account to another EOS key pair?

Question

Suppose account aaa is associated with pubkey1. Is there a way to completely transfer ownership of account aaa to another public key pubkey2 ? The desired result is only pubkey2 can be used to authorize actions while pubkey1 can't do anything.

Answer 1

Yes, you can.

Original fff account's owner key and active key are EOS4zQiTie***tBQ4.

bob@bob-VirtualBox:~/eosio-wallet$ cleos get account fff
permissions: 
     owner     1:    1 EOS4zQiTiebtvcQqUe1t2Bkn4aLZcdRWR5NcqAZ4bsXxHyBP1tBQ4
        active     1:    1 EOS4zQiTiebtvcQqUe1t2Bkn4aLZcdRWR5NcqAZ4bsXxHyBP1tBQ4
memory: 
     quota:       unlimited  used:      2.66 KiB  

net bandwidth: 
     used:               unlimited
     available:          unlimited
     limit:              unlimited

cpu bandwidth:
     used:               unlimited
     available:          unlimited
     limit:              unlimited

First update owner key.

bob@bob-VirtualBox:~/eosio-wallet$ cleos set account permission fff owner EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV -p fff@owner
executed transaction: dbe50e1f6c350d46c1b75fc9815776c7347a3b5e37bf9f6723ae8a316f0616b8  160 bytes  177 us
#         eosio <= eosio::updateauth            {"account":"fff","permission":"owner","parent":"","auth":{"threshold":1,"keys":[{"key":"EOS6MRyAjQq8...
warning: transaction executed locally, but may not be confirmed by the network yet

And now let's query fff's account.

bob@bob-VirtualBox:~/eosio-wallet$ cleos get account fff
    permissions: 
         owner     1:    1 EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
            active     1:    1 EOS4zQiTiebtvcQqUe1t2Bkn4aLZcdRWR5NcqAZ4bsXxHyBP1tBQ4
    memory: 
         quota:       unlimited  used:      2.66 KiB  

    net bandwidth: 
         used:               unlimited
         available:          unlimited
         limit:              unlimited

    cpu bandwidth:
         used:               unlimited
         available:          unlimited
         limit:              unlimited

As you can see, owner key already updated. Now update active key.

bob@bob-VirtualBox:~/eosio-wallet$ cleos set account permission fff  active '{"threshold": 1, "keys": [{"key": "EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV", "weight": 1}], "accounts": []}' owner
executed transaction: 8f39cb0171e3cd3ebf2dbd848f73d1cade0cccee9a2a15bc4e2484335d9cce17  160 bytes  208 us
#         eosio <= eosio::updateauth            {"account":"fff","permission":"active","parent":"owner","auth":{"threshold":1,"keys":[{"key":"EOS6MR...
warning: transaction executed locally, but may not be confirmed by the network yet

Let's query fff's account.

bob@bob-VirtualBox:~/eosio-wallet$ cleos get account fff
permissions: 
     owner     1:    1 EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
        active     1:    1 EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
memory: 
     quota:       unlimited  used:      2.66 KiB  

net bandwidth: 
     used:               unlimited
     available:          unlimited
     limit:              unlimited

cpu bandwidth:
     used:               unlimited
     available:          unlimited
     limit:              unlimited

By now, the account fff is transfered from EOS4zQiTie***tBQ4 key's owner to EOS6MRyAj***5GDW5CV key's owner, now it has nothing to do with EOS4zQiTie***tBQ4, EOS6MRyAj***5GDW5CV has full control of fff.