I recently completed a PSU replacement using the ReactiveMicro Universal PSU kit on an 1982 Apple ][+ unit. This is the build log of replacing the old PSU with the new one, as the old one was too aged and only accepted 120V AC (I live in a country that supplies 240V AC). This build log is a complement (not replacement) to the original ReactiveMicro Guide.
Detach the right side of the baseplate. This is the expected position of the PSU on the baseplate, but don't fasten the screws yet.