The best way to disable the master key is to move your funds to a new wallet with a new seed that you are sure no one else has access to. This will ensure that no one else has access to your funds. It is important to remember that anyone with the seed words controls the funds, so if you think someone else has them, it is important to take the necessary steps to protect your funds. To do this, you should create a new wallet with a new seed and transfer your funds to it. This way, you can be sure that no one else has access to your funds.
