Import Yahoo stock prices into Quicken

Quicken allows importing security prices from a .csv files. Therefore, nowadays it is relatively simple to import your own portfolio prices from the web.
I use Yahoo! Finance portfolio as they have most of the securities from all over the world. Their portfolios feature is available to everyone and is quite fast and convenient. You can even create a separate view that includes only the symbol and price, which would perfectly match the export process.
Yahoo Finance - Business Finance, Stock Market, Quotes, News
To import prices into Quicken, do the following:

1. Open your Yahoo portfolio
2. Select and copy the table into clipboard (Ctrl+C)
3. Open a Google spreadsheet
4. Paste the table into an empty sheet
5. Do some preparation here:
1. Delete all columns except the security symbol and price if you are not using a custom view.
2. Customize the symbols - remove extensions with Find/Replace, etc.
6. Use "File -> Download as..." option to download a .csv file
7. In Quicken, use File -> File Import -> Import security prices from .csv file
8. In the pop-up dialog, select the date for the prices. I have not found the correct date format for the date so it is safer to simply select it in the dialog itself.

That's it. The prices should now be imported for all the securities in the portfolio. This can save a significant amount of time and effort.
Note that the instructions refer to Quicken 2014 for Windows. The other software involved is pretty generic or online so should be available on all platforms.