Hey, I replace all my flag staffs with wire (I use H&R 5 mm nap figs). This is what I do:

1. Cut the cast flag and staff off the figure.

2. Trim and shave, and trim and shave, around the figure to make it look "better".

3. clamp the stand of the figure to my dremel drillpress mount (I didn't always have one of these, so you might want to skip to the actually firing up of the drill).

4. Insert a 0.0018 drill into my handy dremel, and make sure it is plugged into the rheostat . This little gadget makes the current flowing to my drill variable, so I can change speeds easily.

5. Carefully, drill through the hands and into the stand of the figure. Just don't drill all the way through the stand.

6. Measure a length of wire (hobby store, about 35 cents USD) .018 gauge long enough to clear the figures head by the height of the flag (or a little less, as you desire). Insert the wire through the hands and into the stand. Glue in place with cyanacrylate (superglue) as you do so. Let dry at least 24 hours. Nothing more frustrating than painting a 5-6 mm fig and have the darn flag staff fall out.

I've done literally hundreds of these (including cavalry and Masts for 1/6000 ships WW2). Good luck. P.s. I go to warflags for my paper flags. So much easier in this scale to cut and paste rather than paint by hand (besides, my eagles always look like rats, or green-pawed cats. (GRIN!!!).