So far, I've found that you can most likely just use your original domain directory, which is where the vast bulk of the configuration goes anyway.
So, in the simplest case, I would just install the latest release and copy domain1 out of the old one and plop it in the domain directory of the new release and fire it up. That's worked for me in the past.
If you already move your domains out of the GF install, you don't have to do anything at all.
If you've made actual changes to the GF install (outside the domain), then you're stuck moving those manually. But I don't recall having to yet do that myself.
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