Using the following script, the DYNSA login will be recreated and configured as dbo for you.
/****** Object: Login [DYNSA] Script Date: 02/04/2012 21:54:45 ******/
IF EXISTS (SELECT * FROM sys.server_principals WHERE name = N'DYNSA')
DROP LOGIN [DYNSA]
GO
/* For security reasons the login is created disabled and with a random password. */
/****** Object: Login [DYNSA] Script Date: 02/04/2012 21:54:45 ******/
CREATE LOGIN [DYNSA] WITH PASSWORD=N'= 5kG èÇ„CŽü"Ô °V¤%óug ÁÓ_·', DEFAULT_DATABASE=[master], DEFAULT_LANGUAGE=[us_english], CHECK_EXPIRATION=OFF, CHECK_POLICY=OFF
GO
EXEC sys.sp_addsrvrolemember @loginame = N'DYNSA', @rolename = N'securityadmin'
GO
EXEC sys.sp_addsrvrolemember @loginame = N'DYNSA', @rolename = N'dbcreator'
GO
ALTER LOGIN [DYNSA] ENABLE;
GO
USE master;
GO
ALTER AUTHORIZATION ON DATABASE::DYNAMICS TO DYNSA;
GO
USE DYNAMICS;
GO
DECLARE @interid VARCHAR(10);
DECLARE @sqlstmt NVARCHAR(500);
DECLARE c_company CURSOR FOR SELECT INTERID FROM SY01500;
OPEN c_company;
FETCH NEXT FROM c_company INTO @interid;
WHILE @@FETCH_STATUS = 0
BEGIN
SET @sqlstmt = 'ALTER AUTHORIZATION ON DATABASE::' + RTRIM(@interid) + ' TO DYNSA';
EXEC sp_executesql @sqlstmt;
FETCH NEXT FROM c_company INTO @interid;
END
CLOSE c_company;
DEALLOCATE c_company;
GO
/* End of script */
Note: Reset the DYNSA password via Dynamics GP - User Setup window afterwards if desired.