Don't worry about it. Auditors won't like me for saying this, but the 82304 doesn't contain much additional content on top of the 62304. Just comply with the 62304.

I could write a lengthy answer to this one, but there's no reason to. The IEC 82304 is a standard which, in simple terms, aims to provide some clarifications on top of the IEC 62304. It mostly deals about validation of your software.

Some auditors expect you to "comply" with the IEC 82304, but this isn't a general expectation. Regardless, "complying" with the 82304, as a minimalist, would simply mean adding it to your list of applicable regulations and.. that's it. Because you're already complying with the 62304 and that already covers you pretty well for the 82304, there's simply not much you need to do on top.

Oh, and if you were wondering where to get the IEC 82304, use the friendly Estonian site to save lots of money, as always. In case you didn't know about the Estonian site yet, here's an explanation and here's a video. And here's a direct link to the IEC 82304 over there - at the time of writing, the price for the IEC 82304 on the Estonian site is ~24€, while the "normal" price is ~250€, if you can consider that "normal", given that you're paying money for a PDF.