Step 1: Stand sideways and roll the ball forwards into space using the sole of the foot
Step 2: Place active foot down next to the other foot ‘behind’ the path of the ball, place the other foot in front of the ball like a ‘step-over’
Step 3: Bring back your foot in front of the ball to join the other foot to cross your legs
Step 4: Bring your front foot back, behind you, don’t touch the ball
Also, try to practice a start with your other foot;)
Cristiano Ronaldo Reverse Step-Over Soccer Trick Tutorial Video