In this tutorial, we will walk you through the steps of editing a template file in Joomla 3.
Log into your joomla 3 admin dashboard
In the top menu, click Extensions and then click Template Manager
In the left menu, click Templates
You will see a listing of templates you have installed. Find the template you want to edit, and then click the Template Details and Files link.
Click the file you want to edit
You are now on the Customise Template page. The left menu of the page shows Template Master Files and in the right menu it says Stylesheets. Click any of the files in those two lists to edit the corresponding file. Below is a list of the files that you can edit:
Edit main page template: index.php
Edit error page template: error.php
Edit print view template: component.php
Edit css/template.css: css/template.css
Edit the file and then click Save
After clicking one of the above files, you'll be brought to the Template Manager: Edit File page. On this page you will see an editor that you can use to edit the code of the file you chose. Make the changes you wish, and then click the Save button in the top menu. Congratulations, you just edited your template!
Results of our Joomla 3.0 testing
In our testing, we were working with Protostar Details and Files and chose the Edit main page template option. Under the opening of the body tag, we added the following text:
Look, I edited my template!
Below you can see screenshots showing where we made the edit, and how it changed our template: