how to implement SPI protocol on MSP430fg4618

Note how the forum has automatically highlighted the part number - making it a link to the Product Page.

The Product Page contains everything you need:

Study the Datasheet and the Family User's Guide to find out how to use the SPI functions of this chip!

Look at the Software Examples: http://www.ti.com/product/MSP430FG4618#softTool

Follow the Links for Support, Training, Wikis, etc,...

Google for 3rd-party sites such as http://www.43oh.com/