Some users of OneStepCheckout needs to change the <title> of the checkout page in order to better match their site (translate into local language, and so on). In order to change the title of the page, you need to make a change to the '''onestepcheckout.xml''' layout file that comes with Magento.
First you need to find the correct XML file to change.
If you want your change to work through upgrades, you will need to copy the onestepcheckout.xml file from default/default/layout or base/default/layout to default/yourthemename/layout. Then you can make the changes there, and they will be kept when you upgrade with a newer version of OneStepCheckout.
In order to change the text, open the XML fine in your favorite editor and search for: <code><action method="setTitle"><title>One Step Checkout</title></action></code>
Change the contents between <title> and save. Then you need to refresh your cache, before accessing the checkout in the frontend. The title should now be updated.