Just like multiplying any other fractions: Numerator times numerator over denominator times denominator. Then you need to collect like terms.
Hint: Here you can simplify the problem before you perform the multiplication. Factor the denominator in the left-hand fraction and the numerator in the right-hand fraction. You will find that they have a factor in common that can be eliminated before the multiplication, greatly simplifying the arithmetic.
John
My calculator said it, I believe it, that settles it