Just to clarify, and I’m guessing here by reading between the lines…
You have your local library of music currently on a USB-connected spinning disc, and its temperature is worrisome to you?
You want to transfer all your music to an external SSD?
And you want to make sure that your library recognizes the files on the new location as the same as the ones at the old location so you don’t lose play counts, etc?
Can you confirm the details of your situation and what you’re trying to acheive? If I’m right above there are a few threads I can point you to, and it’s fairly simple if you do it the right way. But we’ll need to know what you’re up to and what your situation is in detail.