Splitting a bank transaction into an interest income and a transfer of (portion of) invested principal

I have a certificate of deposit with 10k in it. Say over time it generates 300$ in interest income.

At the time of CD renewal I decide to reduce the investment, so I transfer the interest and part of the principal (say, 2k) back to my main checking account. So I see a bank transfer of 2,300$ to the checking account. CD account now has 8k in it.

I need to properly categorize this transfer into what it is: a $300 interest income and a 2,000$ transfer from the CD account to the checking account.

What's the best way to accomplish this? Note that my bank transactions are automatically downloaded from the online bank.