Use either an incline bench or a flat bench and start with 7 full reps of dumbbell presses. Then do 7 bottom-half partials followed by 7 top-half partials where you consciously try to squeeze your chest at the top of every rep.
Selecting the right weight requires a bit of guesswork at first, so start conservative with a weight you can get for 16-17 reps and build from there.