There are several old (around 2009) questions on SO addressing this issue, for example:
How do I update a Linq to SQL dbml file?
Just to confirm, is it still the case that VS2010 does not (and can not) automatically update LinqToSQL DBML files when a schema change occurs in the underlying database? So one must still either delete all tables from the existing DBML diagram and re-add, or use one of the 3rd party offerings to do the code generation, is this correct??
(If so, recommendations on the latest/greatest 3rd party tool, including price, would likely be helpful to others).