<p>Sir Jim Ratcliffe sits down with BBC sports editor Dan Roan after completing his deal to buy a 27.7 per cent stake in Manchester United. </p><p>The British billionaire's investment is worth about £1.25bn. </p><p>He says it's a boyhood dream to be involved in United and that restoring them to the pinnacle of English and European football is the greatest challenge. </p><p>Sir Jim also discusses how it's his "preference" to build a new stadium for the club that can also "serve the north of England".</p><p>Producer: Jonathan McKeith</p>