Hi Sani,
I ran into this after a DBA left and didn't document his work. Unfortunately I couldn't find any way to reset the password and one reference in the Hitchhiker's Guied to SQL Server 2000 Reporting Services that said you can't reset the password except from within the package.
Fortunately someone was able to guess it. There isn't a lock out on the number of failed logins to a DTS package. Good luck!
Tim