Need help with another SQL query

I have a few telephone numbers for each record in a table. I want to search all fields within a table for telephone numbers in the format of:
(123) 555-5555 and change it to 123-555-5555

How would I go about doing that?

Many thanks,

assuming there’s nothing before or after the phone number…

also assuming mysql, because, well, because you didn’t specify your database system…

UPDATE daTable
   SET daColumn = CONCAT( SUBSTRING(daColumn FROM 2 FOR 3) -- 213
                        , '-'
                        , SUBSTRING(daColumn FROM 7 FOR 9) -- 555-5555
 WHERE daColumn LIKE '(___)____-____'