Declare @TableName Varchar(60)
Declare @FieldName Varchar(50)
Declare @DefaultName Varchar(100)
Declare @StrCommand varchar(1000)

Declare ChangeDefaultField cursor For
Select sysobjects.name Tables, syscolumns.name,  object_name(cdefault) as 'NameDefault' From syscolumns 
inner join sysobjects on syscolumns.id = sysobjects.id
Where syscolumns.name in('Store_Code' , 'StoreCode')
And object_name(cdefault) is not null
Open ChangeDefaultField
Fetch Next From ChangeDefaultField Into @TableName, @FieldName, @DefaultName
While @@Fetch_Status = 0 
Begin
  Set @StrCommand = 'Alter Table ' + @TableName + ' Drop CONSTRAINT ' + @DefaultName
  Execute(@StrCommand)
  Fetch Next From ChangeDefaultField Into @TableName, @FieldName, @DefaultName
End
Close ChangeDefaultField
Deallocate ChangeDefaultField