How to replace a substring in a string in mysql code example

Example 1: mysql replace a character in a string

UPDATE users SET first_name = REPLACE (first_name, 'search', 'replace_with') where id > 0;

Example 2: mysql replace text

UPDATE
    table_name
SET
    column_name = REPLACE(column_name, 'text to find', 'text to replace with')
WHERE
    column_name LIKE '%text to find%';