On the new server, you have to install SQL 2008 prior to installing LANDesk Management Suite. Then get a copy of the db restored to it. Actually since you have to install the SQL Server first yourself, you might as well install SQL 2012 and be on the latest and greatest SQL.
- Install SQL on new server prior to installling LDMS (or you may already have an updated SQL server running in your environment).
- Backup SQL 2005 database
- Restore the database to the newer SQL server.
- Verify permissions on the restored DB in the new SQL server.
- Follow all the rest of the side by side procedures, only when selecting the DB, point to the restored DB on the SQL 2008 server.
Hope that helps.