Ok I think we need to take an extra step back
He said he is currently on software version 9.0.0.41
So first question, what type of 3300 ICP have you got? MX, MXe, CX etx (MX cant be upgraded, CX needs a ram upgrade if it only has 256)
then you need to look at your Software Assurance to license the upgrade (as mentioned above), your vendor should be able to check this for you, who should also supply the installer and software.
If you plan to go beyond 4.0 you will need to go to 4.0 and then do a database migration before upgrading any further.
And finally backup backup backup