Just made this change via phone call to Tesla. I moved from 3D to P3D and dropped EAP. I was told the website does have a glitch where it shows updated pricing on the order if I edit myself, but those would be corrected to the lower paint pricing, etc. I had on my original order. Rather than do it myself from the site, they put the change order in for me.
Since the 19's that were on the first order are not avail on the base P3D and I dropped EAP, my new total is just $3500 more. Considering I would have rarely been able to use EAP where I drive the most, but I will love the extra smiles of the P's quickness, a good deal for me.