Hello AlbertSpeer! Welcome to
What do you mean when you say iv'e tried to copy it to the phone but the phone cant find it?
Here is what you can do to install a theme in P1i:
1. Transfer the theme to your Sony Ericsson P1i. You can do this via USB, infrared, or bluetooth
2. In your phone, Open Main menu
3. Open Tools
4. Open File manager
5. Navigate to the themes, and select the transfered theme. @aw
I finished your post, seems that something eat your few last words.