Installing a Tumblr theme is real easy! Just follow these simple steps to get it perfect first time! Whether your downloading a freebie or a premium theme you will be provided with a .html file, this contains all the code you need for your new theme.
1. Open that file up with a text editing program such as NotePad (it’s free!).
2. You want to select and copy everything in this file… every last bit of code. You can easily do this by pressing CTRL + A, then CTRL + C, which will select everything and then copy everything.
3. Log in to your Tumblr account with your login details and click on the Customize Appearance button.
4. Click on the Theme menu item at the top of the Customize page. This will open a drop down showing some of Tumblr’s own free and premium themes. You want to click on the Use Custom HTML button at the bottom of this drop down.
5. This will change the drop down menu and it will show a tonne of code. Select all of that code and delete it… we don’t need that old code any more. Now whilst in this box press CTRL + V, that will paste in your new themes code.
6. Click on Update Preview and that will change the preview from your old theme to the new one. Press the green Save + Close button in the top right.
7. Go to your Tumblr accounts URL and you’ll see that your new theme has now been installed. If your theme has custom options they will be under the Appearance tab when in the Customization mode.
Check out my top selling Tumblr themes on ThemeForest: