New Exhaust Help!!!!

Hey guys and gals,

I'm the owner of a 1993 Chevy Cavalier RS,
I'm looking into purchasing a magnaflow exhaust for it, but
the piped on the magnaflow are quite big, (~3Inch?) and the
pipes on my Cav are quite small (~1.5Inch).

How would I go about installing the piping system?

Thanks

P.S. This is the link to the exhaust..
http://www.canadiantire.ca/AST/browse/4/Auto/AutoCustomPerformance/Exhaust/PRD~0344044P/Magnaflow%252BMuffler%25252C%252B14325.jsp (http://www.canadiantire.ca/AST/browse/4/Auto/AutoCustomPerformance/Exhaust/PRD%7E0344044P/Magnaflow%252BMuffler%25252C%252B14325.jsp)