Jim with The Chip Room has his own subforum:
https://www.pokerchipforum.com/forums/the-chip-room.21/
If you go into that subforum and click the "Watch" button then you'll get notifications (either through messages on the forum or via email, or both, your choice) whenever Jim posts a new thread to that subforum.
Sometime in the next couple of weeks Jim will post a thread promoting the upcoming sale. It will have links to his PayPal store where you can buy the chips, but those links won't go live until the day and time of the sale. When the time approaches, star refreshing that post; when the links go live, click on the links to visit his store and buy the chips you want; you'll need to do it quickly before they sell out.
So:
- "Watch" his subforum
- Wait until he posts his sale thread; you should get a notification
- Read his sale thread so that you know what chips will be sold, how much they cost, what the rules are for buying them, and what day and time the sale will be
- Take the time in advance of the sale to figure out what you want to buy
- Wait until the sale starts
- Refresh the sale post
- Click on the sale links
- Buy
You can look at some of his previous sales to get an idea of how it all works, for example
last year's Jack Cincinnati sale.
Good luck!