Installing Tumblr theme is very simple and easy. There are two types of installing method first one is directly from Tumblr theme garden and the second one is installing Tumblr theme from other websites through copy and paste method. If you bought premium Tumblr themes from ThemeForest or creative market then you need to follow the second method which is copy and paste method.
Browse Best Free Tumblr themes by your needs if you spot out the theme then click “Install Theme”. (Before you started you must be logged on your Tumblr blog. If you not logged in yet click here to login to Tumblr)
Step-1: Ready to Install.
Click “Install” button in the top right corner.
Step-2: Choose blog to Install.
Now the drop-down list will appear and you need to select which blog do you want to install the theme. So select the blog to begin the install.
Step-3: Begin Install.
After Selecting the blog click again on Install Button