Are you familar with SQL? IF so, you can write an update statement - pending all the records you want to update have something in common.
For example, if you have a table called tblTest with the following columns:
numID number ,
txtName text ,
txtAddress text ,
txtCity text ,
txtState text ,
txtZipCode text
And you wanted to update all txtState to = NY
update tblTest
set txtState = "NY"
if you wanted all records where the state name = "NY" then
update tblTest
set txtCity = "test city"
where txtState = "NY"
hope this helps