Step 1: Log into your hosting system via a FTP software

Step 2: Unzip the wr-nitro.zip file and use only the extracted Nitro theme folder

Step 3: Upload the extracted Nitro theme folder onto wp-content > themes folder.

Step 4: Activate the newly installed Nitro by going to Appearance > Themes, find Nitro and click on “Activate” button

Step 5: Once Nitro is activated, you will be redirected to Nitro Welcome Screen. Switch to Plugins tab to install plugins

Step 6: click “Install” to begin installing plugins. After that, you will have to activate plugins.