It won't be straight forward as it has lots of customization that u will have to rewrite if they are missing in xenforo u need to understand php and how vbulletin works in order to be able to do it
Site size compressed is 41 GB so make sure u can do it I have been online since 2001 and never shut down for more than 24 hours
I need to know how long it will take u before u start + if u are good enough I will continue withu for further customization.
I have made custom scripts for moderators to ( Changes user names, change user signature, See who is participating, band users , Custom award titles and listing ) I made this to prevent moderators from accessing the CP they are all working all u have to do is convert them to Xenforo if they are not available. I also have integration with known scripts such as VBtube,file uploader and Photopost.
You will need to put hours into this its not a one day job.
I will share the site in private only