These examples show how to use a DDL query statement to:
   - change the size of a field;
   - change the data type of a field;
   - add a new field to a table;
   - remove a field from a table:

ALTER TABLE MyTable ALTER COLUMN MyText2Change TEXT(100);
ALTER TABLE MyTable ALTER COLUMN MyField DOUBLE;
ALTER TABLE MyTable ADD COLUMN SomeNewField TEXT(60);
ALTER TABLE MyTable DROP COLUMN SomeNewField;

You can execute a string using DAO
   dbEngine(0)(0).Execute strSQL
or ADO:
   CurrentProject.Connection.Execute strSql