That only works on the Aerosoft Beaver (as far as the rotating of the textures goes) the rest of it should be ok if the textures are the same layout.
As Mike says that will get you up and running but the specular textures will still be for the old plane and thus there will be some discrepancies in that area. Try it and see if it works for you. I have been editing all the specular textures too, but leave the bump ones alone.
Also I have found a few of my FS9 textures do not completely line up in FSX and so I have had to tweak some of the repaints especially in the door and cowling areas.