Check the box to the left of it, and choose the «More» icon above the file listing. (androidcowboy.com)
After installation of above file is done which is ROM installation, go back to main menu of CWM and repeat the above step and choose «Gapps zip file» on place of ROM zip and install the Google apps package. (stjsgadgets-portal.com)
OldNewExplorer also allows you to change the appearance of the options bar above the file list and the Details pane. (howtogeek.com)