To replace field values in every record in the found set:1.If necessary, find, omit, or sort the records in the database table.For more information, see Finding, sorting, and replacing data.2.In, in the current record, select the contents of the field you want to replace.3.If you're replacing data with a constant value (instead of serialized numbers or a calculated result), type the value.4.Choose Records menu > Replace Field Contents.5.In the Replace Field Contents dialog box, select an option:A calculated value Replace with calculated result, then click Specify. In the Specify Calculation dialog box, enter the calculation you want evaluated. (The result must match the of the replaced field.) Click OK.Note For more information about the Specify Calculation dialog box, see Specify Calculation dialog box.Repalce HowTo with pictures
You could use find/replace. Select the field then under Edit goto Find/Replace. Enter 1A1 in the find field and 2A1 in the replace field. Click the current field check box and then click replace all.