To delete a variable from a package
1.In Business Intelligence Development Studio, open the Integration Services project that contains the package you want.
2.In Solution Explorer, right-click the package to open it.
3.On the SSIS menu, click Variables. You can optionally display the Variables window by mapping the View.Variables command to a key combination of your choosing on the Keyboard page of the Options dialog box.
4.In the Variables window, click Show User Variables.
5.Select the variable to delete, and then click Delete Variable.
6.If the Confirm Deletion of Variables dialog box opens, click Yes to confirm.
7.To save the updated package, click Save Selected Items on the File menu.