Installation Video
Guide with Screenshots
Step 1 Install Extension
Unpack the downloaded zip file in your Magento root folder.
Delete the contents of the /var/cache folder to force Magento to update its configuration (alternatively refresh the configuration cache in your Magento backend).
Step 2 Prepare an SSL certificate for use with Xero
openssl genrsa -out privatekey.pem 1024

openssl req -newkey rsa:1024 -x509 -key privatekey.pem -out publickey.cer -days 365

openssl pkcs12 -export -out public_privatekey.pfx -inkey privatekey.pem -in publickey.cer

After these steps you should have three files named privatekey.pem, publickey.cer and public_privatekey.pfx

Step 3 Setting up a new Application in Xero
Go to api.xero.com and login with your Xero login

Choose to add a new application Choose "Private"

Enter any information into Application Name
Select the publickey.cer as a X509 certificate
Click Save
Step 4 Configuring Magento
Go to System > Configuration > Fooman Connect

Copy the Oauth Credentials Key to your Magento back-end (Consumer Key)
Copy the Oauth Credentials Secret to your Magento back-end (Consumer Secret)
Copy the contents of the file privatekey.pem to your Magento back-end (Private Key), fill in the Password of Private Key field if you have assigned a password during the generation of the certificate.

Click Save Config
Step 5 Finish setting up
With the provided credentials Magento will now connect to Xero and retrieve information about your organisation. You can configure Fooman Connect with your settings from Xero (Accounts,Tracking Options, etc)

Choose Enable - Yes
Save Config
Step 6 Map Tax Rates
Go to Sales > Tax > Manage Tax Rates & Zones

Go into each individual Tax Rate and choose the appropriate Xero Tax Rate from the dropdown
It is important to map tax rates with the same effective tax rate.

Step 7 Export your Orders Manually
Go to Fooman Connect - Xero Click Process All Unexported Orders or tick the checkboxes next to individual orders and choose Process Selected from the Action dropdown menu and Submit

Go to Xero and review the exported orders under draft invoices

Step 8 Set up Automatic Exports
Go to System > Configuration > Fooman Connect
Choose Enable Automatic Exports - Yes
Save Config

