The site of one of Kent’s largest employers is undergoing a huge overhaul as part of a £220 million cash injection set to bring in hundreds of new jobs. Aerospace and defence giant BAE Systems is transforming its Rochester base in what is one of the largest investments the firm has made in its 25-year history. Part of the funds will go towards a new state-of-the-art factory in Marconi Way to allow the technology giant to continue to expand and meet growing demand. It will replace outdated buildings, some of which date back to the 1960s. Diggers are already on site demolishing previous Elliot B…