1. Flash file (Click here to Download Samsung galaxy s3 Lollipop custom update)
2 kernel (Click here to download Kernel)
Extract the downloaded Galaxy S3 Lollipop ZIP file and copy the ROM back-up file onto > sdcard > clockworkmod > backup.
Boot up your phone in recovery mode.
Next, perform a full data wipe (unless you are running a previous version of this ROM)
Now restore the nandroid backup which you copied to your SD-card
Finally, flash the downloaded kernel