Pathfinder Adventure Paths in 3.5

[Alabenson]

I was wondering, approximately how easy would it be to run a Pathfinder Adventure path in D&D 3.5?

[Aergoth]

Depends, some of the early pathfinder adventure paths (back when it was a setting as opposed to a system) were published under 3.5 rules. the original Rise of the Runelords, Second Darkness and a least one other path, plus early Pathfinder Society stuff runs under 3.5 rules as I recall.

As far as converting from pathfinder down to 3.5 for stuff published under 3.P rules, tricky but doable.