What you need:
1. Good knowledge of CSS/HTML including how to use the Firebug plugin for Firefox and knowledge of how to write efficient code
2. Some graphic design ability
Optional: familiarity with modifying VBulletin v4.2 templates (this could be learnt during this job if you are smart)
I have an existing VBulletin 3 installation which has a customised design based on a commercial VBulletin template. I have bought the VBulletin 4 vanilla version of this same template and I need you to modify it for me so that the design matches my existing VBulletin 3 design. This will mostly involve modifying the header image, but also a few changes to the CSS classes for which you will need to navigate the VBulletin administration interface. This part should take about half a day to complete. For the right person it will be quite an easy job.
VBulletin 4.2 comes with another template for mobile browsers. I also need this template changes so that the design matches the non-mobile template as closely as possible. You will need to use your design skills a little to make judgements about which colours to choose. This is mainly about CSS changes and should take 1 day.
So in summary I think the whole job (parts 1 and 2) should take 12 hours, less for a skilled coder / designer.