How to upgrade Samsung S3 I9300 with CM 12.1(Lollipop 5.1.1) and flash Boeffla Kernel 4.0

Hey ,

Hope you are doing good.

Today, I am gonna help ma fellow S3 owners to breathe a new life into their 3 year old smartphone.

*NOTE :- THIS VERSION OF CM 12.1 IS AN UNOFFICIAL BUILD PORTED BY TWO XDA DEVELOPERS, ARTER97 AND TEMASEK.YOU MAY FIND BUGS, BUT FOR REAL I NEVER ENCOUNTERED WITH ANY BUGS IN MY PHONE AFTER FLASHING THIS.

Installation

The lastest version TWRP (2.8.1.0) or PhilZ Touch recovery is recommended.

Clean Installation
1. Download the appropriate ROM using links provide in the second post.
2. Download the appropriate GApps following the links in the second post.
3. Back up any and all important data.
5. WIPE DALVIK/CACHE/DATA/FACTORY RESET.
6. WIPE SYSTEM.
7. Flash the ROM in recovery.
7.1. DO NOT FIX PERMISSIONS AFTER FLASHING, doing so will cause a bootloop.
8. Flash the GApps.
9. WIPE DALVIK/CACHE (for good measure).
10. Reboot Device.

Dirty Flash/Update
1. Download the appropriate ROM using links provide in the second post.
2. WIPE CACHE/DALVIK.
3. Install the update zip from recovery.
3.1. DO NOT FIX PERMISSIONS AFTER FLASHING, doing so will cause a bootloop.
4. WIPE DALVIK/CACHE (for good measure).
5. Reboot Device.

G-APPS for this ROM

Main Download (XDA DevDB) [Click here] 
Mirror Download (arter97.iptime.org) [Click here] 
Recommended GApps (PA Lollipop GApps) [Click here] 
Alternate GApps (BaNkS Lollipop GApps)

Flashing Boeffla kernel for Max Performance

http://hibbydabby.blogspot.com /2015/12/flashing-boeffla-kernel-4.0-latest-for-max-performance-sgs3.html" target="_blank"> Flashing Boeffla Kernel 4.0(Latest) for Max Performance on Samsung S3

I prefer you to flash the latest SuperSU from Chainfire.eu(After flashing the above kernel and ROM).

FIX - SuperSU has stopped after flashing Boeffla 4.0 Kernel

http://hibbydabby.blogspot.com /2015/12/fix-supersu-has-stopped-after-flashing-boeffla-4.0.html" target="_blank">http://www.hibbydabby.blogspot.com/2015/12/fix-supersu-has-stopped-after-flashing-boeffla-4.0.html

Feel free to comment :)