You access the template editor using the GUI dashboard Template menu selection, where you will find (among other options) the "Edit HTML" button. Clicking on "Edit HTML", you may get a serious warning to read.
Directly editing HTML may affect the way some features work and is only recommended for advanced users. Editing template HTML may unpredictably affect other Blogger features. We recommend using the Template Designer first, where you can Add CSS under the Advanced section.Should you choose to click on "Proceed", you'll be into the "Edit HTML" display.
With a Classic template, you have just one major activity when you're in "Edit HTML" - and that's what the name suggests, you edit the HTML. You'll have some CSS code, but no XML - so it's all relatively straightforward.
With a Layout template, you'll have a few extra options.
- Backup ("Download a copy") the template.
- Upload the template ("Backup / Restore").
- Revert widget templates to default.
- Revert to classic templates.
With a Designer template, you'll have one additional minor option.
And with a layout template, you'll have "Edit HTML", but with a few more tweaks than with a classic template. You'll have CSS and HTML - and XML - code to edit. And don't overlook the possibility of using HTML code in place of XML code, in a layout template.
One of the least understood selections in the Template "Edit HTML" wizard is the option to "Expand Widget Templates" , which has been replaced by selectively unfolding any gadget to be edited. Just understand when to unfold - and when to not unfold.