I haven't done so, but I have been converting Rise of the Runelords and Curse of the Crimson Throne to 5e (both Pathfinder Adventure Paths), and here's what I've come up with as far as ideas go.
1. Skill DCs. The majority of these are 5-8 higher than the equivalent 5e skill checks. You'll also have to work out what skill checks replace what, but I find that to be fairly easy, as 5e's skill system is very simple and straightforward. Rely on your first gut instinct, and you'll be fine.
2. Gold & Magic Items. Throw them out completely. Buy the DMG if you can, and use the random tables in there to generate treasure and available magic items. If you can't buy the DMG, there are some
treasure generators floating around.
3. Monsters. Pathfinder has a buttload more monsters than 5e does. You'll have to do a lot of converting, but, again, the DMG can save you, because in Chapter 9, there's an amazing little table that lets you get in the ballpark for a given CR, and then I just convert over the fluff from Pathfinder. It works very well (err on the side of more HP if you're worried it'll be too easy or hard).
4. Railroad. Pathfinder adventures have a tendency to be a bit railroady; I haven't actually read Emerald Spire, but I wouldn't be surprised--given what it's about--if that's even more so. Don't be afraid to (again!) use the DMG to intersperse little side quests here and there.
I guess the best advice is buy the DMG, if you can...I worked overtime to make sure I could afford it, and it's been the best investment I could ever have gotten for being a DM.
