Hmm, sounds pretty easy.

1. Make sure the CD drive is the first boot device (check your BIOS settings).
2. Put the first CD in the CD drive.
3. Boot the computer.
4. Follow the instructions on the screen.

The instructions should be pretty clear if I remember correctly (it's been a while since I've installed the x86 version of Solaris). I like installing the full system and deleting what I don't need but that's me.

Carl