Move users from one store to another (Do not share) - Magento 2.3

Question

I had a store and many customers. Now I have 3 website with 1 store and i store view per each website, and I need to move some of my customers to the other stores, but when I edit a customer, the option to change stores is disabled as you can see in the image below. How can I move these users to other stores?

NOTE:

My users can only buy in one store, I must not share users in my three stores.

UPDATE 1:

These are my website and stores:

This is my user configuration:

Answer 1

Here is an work around for you. Inorder to change default association of customer you have to do some manual stuffs in database[Make sure you do backup of database before performing any database operations directly].

1. Go to database table customer_entity, find the customer entry by customer id.

2. Change the website_id column to the new website where you want to move.

3. Change the store_id column to the new store in the website where you want to move.

Hope it find you helpful.