Update the record from query result
SELECT  *
FROM    Table t
WHERE   1 = 1
        AND EXISTS (Define criteria here)

The above is a select statement. It returns rows stored in a table.
To make this an UPDATE statement, use exactly the same syntax, except instead of using SELECT syntax, use UPDATE syntax.
UPDATE  t
SET     Column1 = 'SomeNeatValue'
        ,Column2 = 'AnotherNeatValue'
FROM    Table t
WHERE   1 = 1
        AND EXISTS (Define criteria here)
    

How you identify which records to select/update is on the developer. If you need assistance, I'd start at www.w3schools.com and bone up on query syntax.