Minecraft forge 1.12.2 does not start?

Following problem my forge minecraft 1.12.2 only opens in winrar and all files are json files, and my cpmputer can't open them… Is there a trick or is it enough to unzip?

I still have to install, right?

Forge only uses Jar or Zip mods

You may not open the installer with WinRaR but run it with Java. If you right click on a .jar file, go to "Open with" and then select the one that says anything about Java.

Did you download the installer on this homepage: http://files.minecraftforge.net/...forge.net/ or another file?
Drag the file to the desktop.
Rename look to: "Installer"
Create a text document
Write in this document:

java -jar Installer.jar

Break

6.1 In the Save menu, press All Text Documents or All Types or something

7.1 Add .bat to the name

8.1 Save the file on the desktop and for it

You need Java to open .jar files.

https://www.java.com/.../download/