If one suddenly changes the equilibrium position of an harmonic oscillator, applying a force for example, the system needs a certain time to reach its new equilibrium state. During this transcient regime, the system oscillates with a progressively decreasing amplitude until the system returns to equilibrium. The relaxation time is an intrinsic property of the system. However, we show that applying an appropriate time dependent force, we decrease the time necessary to reach equilibrium by two orders of magnitude.