upgrading from cassandra 0.7.3 to 0.8.0

[Anurag Gujral]

Hi All,
          I had a cassandra node which was running on cassandra 0.7.3.
Without changing the data directories I installed cassandra 0.8.0 but when I
query data I get timeouts.
Can somehow please guide me how to go about upgrade from cassandra 0.7.3 to
cassandra 0.8.0.

Thanks
Anurag