Is there a proven, good way to learn to three step the 110m high hurdles?

I am shorter (5 foot 3 inches) and have been hurdling for two years. Right now, I usually do 5-7 steps, because I've gotten used to having my left leg as trail leg. I am a senior this year, and learning four step will be hard. My best time within the last two seasons is 19.8 secs. Track starts in a month and I need to gain my varsity spot back. Suggestions?|||practice practice practice