Follow these steps to upload your theme in Blogger:
STEP 1: While exporting the theme in TemplateToaster, you have to add a Google account. And in case you do not have a Google account then add a “New Account” and click the “Ok” option.
STEP 2: Then log in to your administrator dashboard.
STEP 3: Navigate from the left sidebar menu, and open the Template –> Backup/Restore to add the theme. After clicking Backup/Restore you will get a dialog box as shown below.
STEP 4: Now browse and add the .xml file of your template.
STEP 5: Now your theme is successfully uploaded. Also you can view the blog to see your uploaded template.