Click on the Configuration menu on the left hand side of the screen then Partner (Add on) Settings.
Click on Configure Xero.
Click on Add New Connection on the right hand side of the screen.
You will then be redirected to Xero.
Log into your Xero account.
Click on Authorise.
Now Xero has been linked, You now have to fill out your Xero preferences. And you do this by clicking on the drop down box and clicking on the account for example Postage, Freight & Courier and you have to do this for each of the 5 account types.
When you have selected one for each account types click Map accounts.
Congratulations you have now linked Xero to your account.