Possible Duplicate:
Replace in MySQL
I have a fields in sql database, all text. How can I edit text for all fields? For example I have the same word in all fields, and I want it change to something else or delete it completely.
It seems you need another table to store your words.
So, you will be able to delete or update them using regular SQL queries.
Cannot answer more for such a vague question.
I think you have to brute force this. You have to call the UPDATE statement for every column you want to have changed. (If you really have A LOT of columns you can access the metadata of your database to gather the names of all tables and then gather the names of all columns in that tables and create your UPDATE scripts automatically.