To use Proguard, you should use SDK 2.3.3 (API 10). If you wrote your project in API < 10, you should upgrade it:
android update project --name MyApp --target 2 --path ./MyAppProject
to get the target,run command:
Then config your project to use Proguard:
android list targets
For more android command:
If you use Eclipse, choose File>Export to release your project in .apk file.
You should see
proguard directory in your project directory after exported.
NOTE: you should keep
mapping.txtfile each time you release. It helps debug your app later.