Howard and his team-mates were far too good for their lower division hosts and the only surprise was that it took them so long to wrap the game up.
In only the second minute the Hatters intentions were made clear. A brilliant 20-yard shot by Kevin Nicholls was equally well saved by Wycombe's Frank Talia.
The first goal came on 20 minutes, Howard producing a magnificent finish from an Ahmet Brkovic cross from the right.
The first half saw the home side's only shot on target in the whole of the 90 minutes.
Striker Nathan Tyson bursting past Curtis Davies before his shot was well saved by Marlon Beresford.
The killer second goal arrived on 70 minutes, Nicholls this time hitting his shot past the outstretched dive of Talia to the delight of the 2,000 Luton supporters who had made the trip south from Bedfordshire.
The third goal, which was the icing on the Luton cake, came from another Brkovic cross which Howard headed powerfully past the overworked keeper.