Updated README

README.markdown

@@ -3,15 +3,17 @@ Google Checkout
 
 ### Installation
 
-1. Run `script/extension install git://github.com/railsdog/spree-google-checkout.git`
+1. Add `gem 'spree_google_checkout', :git => "git://github.com/railsdog/spree-google-checkout.git"` to Gemfile
+1. Run `rake spree_google_checkout:install`
 1. Run `rake db:migrate`
 1. Create seller account in Google Checkout
 1. Open `https://sandbox.google.com/checkout/sell/settings?section=Integration` 
 or `https://checkout.google.com/sell/settings?section=Integration`
 1. remember your merchant ID and merchant key
-1. set 'API callback URL' to `http://your.spree.site/google_checkout_notification`
+1. set 'API callback URL' to `https://your.spree.site/google_checkout_notification`
 1. select 'Notification as XML'
 1. Create a billing integration using `http://your.spree.site/admin/payment_methods` and set the merchant ID, etc.
+1. Set `Spree::Config[:allow_ssl_in_production]` to true
 
 
 ### Usage