The best way to go about this?

[inspiration100]

I have been using an expired 3.8 license that had an old 4.0 version when updates stopped. I recently purchased a 4.0 suite license and I want to upgrade my forum from 4.0.7 to my new publishing suite. What is the best way to upgrade my forum?

Do I delete the old files, add the database, and then install the new license?
Do I somehow upgrade the old license (even though it's different vbulletin number?)
Will my old layout work for vbulletin suite (the blog and all)?

Thanks for the help!

[ForceHSS]

just upload the new files and use the new customer number but make sure you turn off all plugins first you might have to update most of them also best to remove all custom skins as they wont work and install the new updated ones for them

[Zachery]

Just upgrade, http://www.vbulletin.com/docs/html/upgrade