Yes.its almost plug and play,as all the silencers rubber hangers are in the same position on both 3.0D and 4,8is,thus ensuring that your tailpipes will be straight and even.
6 years ago when I did mine ,I welded ,but there is another option now ,since you can use 63mm(4.8is) to 51mm(3.0D) pipe connectors,so you will just need to cut the 3.OD exhaust pipes and the 4.8is silencers pipes to connect and its all done.
I would then advise you on a remap to take even more advantage of your now ,more free flowing exhaust,and you see an easy and reliable 270bhp /600Nms.(wouldnt go more than this as you have a plastic inlet manifold,a fragile exhaust manifold and more important,the transmission will cope nicely with "just" 600 Nms.
I dont know what part of the country you are,but if you can get to Stroud,Glos,..my coleague Dan Turner race developments south west UK car tuning company has years of experience of this type of work and remaps.