After playing with a few strategies trying to neutralize delta, I settled on a triple calendar that reduced delta by 4. It is not an easy job to make large delta adjustments while maintaining a smooth P&L curve and it's not necessary to cut delta to 0 in one shot. I placed 3 separate calendar orders with $0.10 above mid prices. They all got filled in a few minutes.
The following image was simulated to record the P&L graph before adjustment and showed movement of break even points.