To solve this, just multiply 2 years by the conversion factors in a way so that the units cancel out. If year is in the numerator, than you should be multiplying it by a conversion in which year is in the denominator so that years will cancel.
( 2 years ) x ( 365.25 days / 1 year ) = 730.5 days
( 730.5 days ) x ( 24 hours / 1 day ) = 17532 hours