Running an AD&D adventure ("The Ghost of Harrow Hill") in 5e; any advice?

[JonBeowulf]

Has anyone who's run AD&D adventures in 5e before got any thoughts on the above, or tips?

I've done it with Dark Clouds Gather. You have a ton of work ahead of you. You'll need to rework every encounter to ensure it's the appropriate challenge based on 5e assumptions and PC abilities, you'll need to swap creatures that did not make it all the way to 5e, you'll need to tweak BBEG powers (you already know that), and I'm sure there are a few other things I did that I don't remember now.

It was worth it, but damn it was a lot of pre-work.