Reinstalling Exchange 5.5 Correctly

We were attacked by the I-Love-You.vbs when it first came about when no one had protection. It deleted our html files and graphics as well as graphics for symantec nav for exchange. How do I go about:
1. uninstalling the iis 4.0 and reinstallingit properly.
2. uninstalling NAV for exchange
3. reinstalling web access for exchange 5.5
4. reinstalling NAV for exchange

Do I :

1. uninstall nav for exchange.
2. disable exchange internet access.
3. uninstall options 4.0
4. delete any left over files for webpages.
5. reboot.
6. reinstall options 4.0
7. reinstall sp6a.
8. reinstall exchange 5.5 web access
9. install exchange sp4
10. install nav for exchange

If this is correct, what are the specific steps for #4 and #8? If not correct, what?

Please reply ASAP.
Thank you.