Here its a video tutorial ( http://youtu.be/mAJkVWND1CM or this http://youtu.be/qSQKbUIsc7c ) to help you install new template.
Follow Most Simple Guide to Install your Favorite Blogger Template.
1. Click in Download button and save file in PC [hard drive].
2. File that you have downloaded is .ZIP file so need to be extracted. Extract / Unzip it.
3. Log in Blogger dashboard
4. Click Template (or Design > Edit HTML > Upload) and look at the top right corner, you will see Backup / Restore button
5. Click Manage and on pop-up windows Browse button and look for folder that is created after extracted file that you have downloaded.
6. Folder has a XML file and TXT file or Internet shortcut, you select only XML file.
8. Click Upload button.
9. Confirm and Save.
That's it.