Question : Updating an identity column

I have an ms sql server database table, with an identity column.  What I need to do is to turn off identity and the update all rows then turn the identity back on.  The column is also the primary key. can anyone assist?

Answer : Updating an identity column

Use SET IDENTITY_INSERT to allow updates/inserts to the identity column.

set identity_insert tbl on;
update tbl set idcol = somenewformula;
set identity_insert tbl off;