Instructions for Linux (only):
Download ChromeCSV for Linux (there is a Windows version). Set as executable (permissions), exit Chromium/Chrome, run terminal:
$ chromium --password-store=basic
(Google Chrome: $ google-chrome --password-store=basic)
Give time to sync, exit Chromium, run terminal in ChromeCSV folder:
$ ./chromecsv ~/.config/chromium/
(Google Chrome: $ ./chromecsv ~/.config/google-chrome/)
ChromeCSV will export file passwords.csv to same folder it is.
Open CSV file in text editor, add first line:
# Generated by Password Exporter; Export format 1.0.4; Encrypted: false
Next, make sure CSV headers are something like this (quotation marks included):
Any other headers expendable. Save CSV file. (My file is in UTF8 BOM)
Run Firefox, install addon 'Password Exporter'
Next, go to Preferences > Security> Import/Export Passwords
Click 'Import Passwords' and select CSV file. Click Open. It will import passwords, skip duplicates.