If you are worried about losing detail, you can try this:
Fill the holes, then sand with a piece of sandpaper taped to the end of a handle. This handle can be some balsa spar, plastic rod, anything you can use to get down, right where you need to sand.
Once the hole is filled/sanded, you may still have lost some detail. But the total loss is small and you should be able to replace whatever got sanded away.
Hope this helps!
