To install 7-Zip FAR Plugin:
1) Create "7-Zip" folder in ...\Program Files\Far\Plugins folder.
2) Copy all files from "FAR" folder of this package to created folder.
*3) Install 7-Zip, or copy 7z.dll from 7-Zip to Program Files\Far\Plugins\7-Zip*
4) Restart FAR.
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7z1801-extra.7z doesn't contain any 7z.dll which need to copy to Far manager 7zip plugin's folder, so it doesn't work at all.