This sql script will change the ownership of table to dbo

DECLARE @old sysname, @new sysname, @sql varchar(1000)

SELECT
@old = ‘oldOwner_CHANGE_THIS’
, @new = ‘dbo’
, @sql = ‘
IF EXISTS (SELECT NULL FROM INFORMATION_SCHEMA.TABLES
WHERE
QUOTENAME(TABLE_SCHEMA)+”.”+QUOTENAME(TABLE_NAME ) = ”?”
AND TABLE_SCHEMA = ”’ + @old + ”’
)
EXECUTE sp_changeobjectowner ”?”, ”’ + @new + ””

EXECUTE sp_MSforeachtable @sql

To change owner for single table use

ALTER SCHEMA NewOwner TRANSFER CurrentOwner.TableName;