PJ will use smoke and mirrors. Plus a lot of time compression, we will see them starting out in one shot, "Well, here we are going to Minas Tirith rideing upon Shaddowfax with Gandalf," and in the next, "So Pippin here we are in Gondor's capitol city. "When I introduce you to the Lord Denethor, keep your trap shut; say nothing about Frodo's mission or Aragorn."
The crooked, straight, and steep stairs will each only have '39 Steps', while the undulating, jagged, and curved stairs will only consist of '12 Steps' each.
Shelob's tunnel will be skipped because we can't see in the dark anyway, so we will go in and come out looking dishoveled and holding Galadriel's star-glass.
I could go on, but why ruin a perfectly good story; I'll leave that up to PJ, after all he is getting paid to do it.