-Complete the W-4 form and provide it to the HR. Thus, the HR will not withheld his FICA tax (this kind of tax is called FICA tax).
Print this IRS document and show it to the HR if they do not understand this IRS rule for F-1 student:
http://www.irs.gov/Individuals/International-Taxpayers/Foreign-Student-Liability-for-Social-Security-and-Medicare-Taxes
http://business.nd.edu/Accountancy/TAP/FICA_Exemptions/