You can check your progress towards this achievement from the Career Menu by going to "Awards and Stats," then "Collectors Chips," and finally "Pro Player Takedowns." You must personally knock out (win a hand in which you take the last of their remaining chips) each of the players listed on this screen, 25 in total.
That being said, you will most likely get this achievement while working towards winning each event in the Career. If you do not have it by the time you play at the 4th venue, Caesar's Palace Las Vegas, check the Pro Player Takedowns screen and make note of which players you need to knock out, then keep your eyes peeled for them in the remaining events. Alternately, you can wait until you play the Tournament of Champions - every pro player is in this event, so your odds of encountering them here is quite high. You can restart it until they are on your starting table if you like.
I have heard that you cannot get Chris Ferguson's chip until the final table at the ToC, but I had it in my collection before that somehow, so it appears that isn't the case.
In any event, good hunting!