This is a rolling release, there is no need to re-install your already running the latest version.
IMHO, the only reasons to ever re-install a rolling distrobution is if you absolutely need the latest default configurations set up for you, or you somehow unrecoverable broke your system.
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After install to the hard drive you would open the Manjaro Settings Manager > Hardware Detection and install the Non-Free (proprietary drivers) from there. Do Not use the arch method, Netrunner Rolling (Manjaro) has a different graphics stack and the config files are not in the same places. You can also use MHWD from the command line to set up drivers: