How to work around the downloading process by just coping files

I had once downloaded UE4 on my pc but later I had to format it due to some reasons.But before formatting i had saved all the installed files of UE4. Now I wanted to install UE4 again and hence downloaded the source via Github. But now I am asked to download further 4 gb from the Setup.bat file. Can anyone tell me how to work it out just by coping the saved UE4 files as I have a very slow net connection.