If your broker handles NASDAQ then there's nothing to do. Your ASX shares will automatically convert to NASDAQ.
If your broker doesn't handle NASDAQ then you are in for a world of hassle. They will get transferred to a US entity and you will have to spend endless hours on long distance phone calls to get them moved to an Aussie broker.
If possible, open an account with an Aussie broker who handles NASDAQ and move your SZL to that broker before Jan.
SZL Price at posting:
$21.50 Sentiment: Hold Disclosure: Held