Hello & welcome to BBF!
Follow these steps. Double click on or right click on the zip file to extract the .alx file. Leave it where it is.
Plug in BB, open desktop manager, click on application loader then click add, browse to and click on the alx file. This putsthe file in the loader. Click next, then either next again or finish.
If you are receiving the error message ' no applications for your device.......' then you need to download and install onto your pc the version of the OS software that is on your BB.
To check your version go to options > about.
Your carrier will have a BB downloads page for you to download the correct OS.