1. Creat two variables with string data type  in the package,set the default values as xml file path and xml schema path
  2. In  CONTROL FLOW tab, select the data flow step that contains the XML Source step (Do not go into the dataflow, it must be done in control flow).
  3. Bring up its properties (right-click > Properties)
  4. Click the elipsis button next to EXPRESSIONS
  5. Select the [XML Source].[XMLSchemaDefinition] property then hit the elipsis button to the right of the Expression textbox.
  6. Drag and Drop your variable that holds your XSD path into the expression box, you should be able to evaluate expression here.
  7. Do similar to XML source file
  8. Click OK
  9. Click OK again
  10. Done