I read the wikipedia article on EAL (http://en.wikipedia.org/wiki/Evaluation_Assurance_Level) but didn't find it very helpful in laying out the steps needed to achieve EAL4. Can someone please lay out in plain English what's involved and what's required?
This is detailed in the documents available from the Common Criteria portal at http://www.commoncriteriaportal.org/. Specifically, you need to read the Common Criteria Part 3 doc.
It's a lengthy and expensive process, and has plenty of critics; for a good summary see this article: http://gcn.com/articles/2007/08/10/under-attack.aspx