What you need to do is work out (from DBCC Page) what the values for the primary key are for those rows. Then do an update (using those pk values in the where clause) to set that column to a valid value. Having no idea what that is, I'd probably start with updating to 0, then do further investigation later.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability