What two steps are necessary in order to import data into sub-forms?

Import data into the parent records (or verify parent records exist), and then import the data into the sub-forms.

Import the sub-form data first, and then link the sub-form records to the parent records using a cross-reference field.

Set the application to Retired status prior to performing the import, and then return the application to Production status.

Use a second tab in your spreadsheet to load the sub-form data, and then configure the data import manager to accept .XLS files.