I had to tweak many individual encounters to match what I wanted. So running it requires looking at the adventure and looking my notes for things to override.
I customize commercial adventures regularly and pretty extensively. I find buying and running the adventure in some digital format to be very helpful. If I buy a Foundry adventure, editing everything is a built in feature. If I buy a PDF, I copy text over from the PDF into my own digital notes and edit them. This way, I end up with a fully integrated adventure with whatever I want to pull from the commercial text integrated right along with whatever changes I want to make.