Hi Zhang,
For install/upgrade ST-PI first you need to run report rtcctool to get required software version and after that download the required Package from SMP.
Deploy the package through SAINT by login with client 000 and use SPAM to define component deployment (ST-PI) for upgrade.
In addition please follow SAP Note 1228899 - Upgrade with ST-PI 2008_1 (Solution Tools plug-in)
Regards,
Gaurav