Mini Processor How Much Would It Cost To Upgrade My Mac Mini's Processor To 1.66 Ghz Intel Core Duo ?

How much would it cost to upgrade my Mac Mini's Processor to 1.66 Ghz Intel Core Duo ? - mini processor

I bought the Mac mini Core Solo version for $ 599 and now Apple makes $ 599 version to 1.66 GHz Intel Core Duo. Can I Have instructions, please? I got my first PC, and work in 2004. But no Mac-PC.