How do I send invites to Google + to all my Facebook friends?

[Manuel]

A site I went to told me to get a Yahoo account, then from there import all my Facebook friends as contacts. Then on Google + just add the contacts from Yahoo onto Google +. However, when I try to import Yahoo contacts with all my Facebook friend's emails, it tells me: "Sorry, we couldn't find any eligible contacts from yourYahoo! account. Please ensure its address book has contacts with valid email addresses and try again". Can anyone explain why it would be saying this?
Umm if you read my question, that is exactly what I tried and it didn't work.

[RetirementForum]

How to Invite Facebook friends in Google plus
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After signing up with Google plus, you can use it and invite people with their email Id to include into your Google plus circle9s). Unfortunately, there is no option in Google plus to invite your Facebook friends directly from there. But there is still a way to do that.
Google plus allows to invite friends from Yahoo and Hotmail account’s contact list and you use this feature to invite all of your Facebook friends at your Google plus profile. Here is the quick guide lines to invite Facebook friends via your Yahoo or Hotmail account.
1. Sign in to your Yahoo or Hotmail account. If you do not have one, sign up for it. Here I am using the Hotmail account to show the workarounds step by step. The similar procedure is applicable also for the Yahoo account.
2. In your Hotmail account’s home page, you can find an option to connect services like Facebook, MySpace, LinkedIn etc. ,...Check out my source for detailed info with pictures!