Long ago, I wanted to revert auto increment value to its original value which starts as 1 in MSSQL 2008.
This is possible by either dropping and recreating the column or do a RESEED through DBCC CHECKIDENT.
DBCC CHECKIDENT ("{myTable}", RESEED, 1);
Another way is provided that there are no foreign keys you can also do
TRUNCATE TABLE YourTableName