Thanks Alan, I'll try your exporting re importing suggestion.
@thomthom: Thanks for your suggestion. well, some models come in low poly acad, dxf format which needs to be converted in to high poly ones. by high poly i mean at least have parts like pipe tube having around 12 segments. downloaded 3ds models are usually very high poly having more details than i required (especially furniture like sofa). Hence i was seeking both solutions.
@ solo: Thanks for the offer. here is the link of megaupload
http://www.megaupload.com/?d=PYKDLF68