Need help with Winrar and Kernal v1.18

Hey everyone, when I try to extract the R4_v1.18_English.zip using Winrar it just dosent want to :-\ It extracts the file but when I look in the newly extracted file, there is nothing in it to allow me to install the software :( So can someone help me with this please?As you can see I am new at using winrar.Thanks.

you install it by copying the files to your microsd and overwriting the ones that are already there.