Hawaii does not tax military retired pay. Your military pension is fully exempt from Hawaii income tax. Thrift Savings Plan withdrawals are a separate thing and are still taxable, and taking them early can cost you more.
There is nothing to apply for. Leave your military retired pay out of the income you report on your Hawaii return. If Hawaii tax was withheld from it by mistake, file a return to claim the refund.
Your Form 1099-R showing the retired pay, kept with your tax records.
