1. Create a query of the gifts that need to be soft credited.
  2. Create a gift export in comma separated values (CSV) format based on the query created in step 1.
  3. On the Output tab, select Import ID.
  4. Click Create Now to create the CSV file.
  5. Open the CSV file.
  6. Add a column with the headers SoftCredAmt (for Soft Credit Amount) and SoftCredRecip (for Soft Credit Recipient).
  7. Populate the Soft Credit Amount and Soft Credit Recipient columns with the appropriate values.
  8. Save and close the CSV file.
  9. Import the soft credits.

OR

Soft credit the past gifts manually.