RaceDay Scoring has a simple way to import existing Races from RunSignUp. 

To get started, click the "Manage Races" button from the main page, or from the "Select a Race" dropdown:

Click the "Import a Race Already On RunSignUp" button:

Then use the date range to search for the Race you are trying to import. 

NOTE: If you are importing a previous year Race, be sure to set the year correctly here.

Once you've set your date range correctly, click "Search".

Next you need to select which RunSignUp Race you'd like to import into RaceDay Scoring

After selecting the Race you'd like to import, RaceDay Scoring will open that Race for you.