There are two ways you can park your NamePros registered domain with Sedo.
Method 1: Change the nameservers.
Click 'Modify Nameservers',
Select 'Use: Your own nameservers',
Enter NS1.SEDOPARKING.COM on the first line and NS2.SEDOPARKING.COM on the second line and submit.
OR Method 2: Domain forwarding
Domain should be using the default "our nameservers",
From the management page, scroll down to the 'hosts' section. There is probably a few entries already there with an IP address. Replace the IP address in each existing row with this URL:
http://www.sedoparking.com/domain.com
(use your actual domain name instead of domain.com)
For each row's 'Record Type', select "URL Frame" or "URL Redirect"
Save changes.