You will need FS2004 (or FSX if you have it) and 3dsmax 8 or 9 (the importer only works with those ones I think, not 3ds max 2008 or 2009).
Download and install 3dripperdx (I would recommend latest beta version)
Start 3dripperdx, select the path to FS. unselect all options on right side. Select Launch. (Make note of the dirs that the model and textures are going to be created in)
From the FS main screen (create a flight), select the aircraft you want to capture. Press F12
Exit FS
Start 3ds Max, select IMPORT, select .3dr and open the dir where the ripper created the capture. Open the file. Unselect all lower options in importer except make sure it is showing the texture in the main screen. Also select the recommended values, take either of the ones that are there. (this will make sure the model is the correct dimensions). Make sure you select Merge into a single mesh (it makes that model cleaner and easier to handle). Select OK.
Voila, your model is now in 3ds Max.
Now , there are couple of things you have to do to get to O2 from here.
1) Your model may look very rough (no smoothing). Simply select the model, go to vertex mode, press Control A (to select all vertices), now select WELD and make sure you select .001 from the spinner. This will weld all vertices that are really close together. This will take a fair amount of time to do. After that you can select a smooth modifier.
2) The model and associated textures are now in one mesh with each texture assigned to a submaterial. I have downloaded a script that populates the material editor
3) The model may be too big (polys) for O2 (Arma) , I would recommend getting poly saver program OR use multires.
