[Galaxy S II Android Development] stylemessiah:
Well that all depends on whether youre up to doing it or not :)

Short answer is: (not suggesting you follow even these hints, i wont be responsible if you do, its why im leaving it vague):

This will send you back to a stock ROM...no point doing this if you plan to flash a different ROM afterwards...you will waste a few hours for nothing....just pointing that out....

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Some people need to put pretty ROM's on their phone and spend weeks/months/years? living here in the support forums for that ROM trying to fix bugs that were never there in the stock ROM and flashing a (hopefully) new fixed ROM every week or so (somertimes nightly), im not one of those....i have tried a lot of non-stock ROMS, but end up back at my modified/tweaked stock ROM because my phone is not a plaything, i need it running 100%, everyday...

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I used to run Cyanogen mod when i was on my old HTC Wildfire eons ago, that was a valid custom ROM flash, the bloated operator ROM was slow and evil and even removing apps didnt improve things). Since then the stock ROM's (even operator customised ones) are far better made and stable.

Manifesto over....here are the basic (purposely) vague steps:

* Find and download latest stock Samsung ROM for your region

* (optionally) Find and download latest stock Samsung radio for your region (these can be later than in the latest ROM)

* Download ODIN

* Download Philz "unsafe" kernel, root and recovery package compatible with your stock Samsung ROM (i.e. they must match)

* Download one of the DorimanX 8.34 tree of kernels, as mentioned im using an older one.

1) Boot Galaxy S2 in download mode

2) Start ODIN on PC and Flash latest stock Samsung ROM for your region

3) After reboot at end of ODIN flash, run through android setup

4) Connect phone to PC and copy Philz "unsafe" kernel and recovery package compatible with your stock Samsung ROM (i.e. they must match) to external sdcard

5) Copy Dorimanx kernel and recovery package to external sdcard

6) Reboot phone into stock recovery

7) Select and flash Philz "unsafe" kernel, root and recovery package (gives you root and recovery without ending up with the dreaded yellow triangle)

8) Reboot phone all the way

9) Shutdown phone

10) Boot phone in recovery mode (new Philz recovery)

11) Flash Dorimanx kernel

11b) Optionally flash latest radio

12) Wipe cache partition, dalvik cache

13) Reboot phone

Hopefully it boots....yup, another warning

13) Open SuperSU (installed by Dorimanx) and use it to remove superuser (installed by Philz)

14) Run STweaks app (installed by Dorimanx) and tweak voltages/OOM etc (note no garauntees on whether your device will allow same undervolting as there are differences across SGS2's. so stability not garaunteed either. Notice all the warnings yet?)

15) Reboot phone

16) Use root app remover app to remove stock ROM apps that you dont need. What i remove may be different than what you would do as i dont use a ton of social crap or even the email client, so it goes. You may not end up with 103 packages removed, personal choices mean different package removal choices and results. Yet another warning: removal of certain packages may result in reduced functionality and stability and worst case a non working phone.

17) Reboot phone

18) Install your normal apps, including BetterBatteryStats (from here in XDA forums). Launch Google Play and do updates

19) Install Greenify / Autostarts for further tweaking if wanted

20) Test phone for a few days....

So yeah, for me to put a followable guide together would take more space, but thats the gist.

I could put together a short guide, but parts of it would be regurgitating from info generally available here via the forums.

At the moment im approaching going in for surgery next week so not really in the best position to sit at the keyboard creating a guide for hours on end. Feel free to ask, but there will be a delay in making it.

This is not something you do without a bit of experience though, but then you have to get experience somehow.

Its also not something you do on a weeknight when you need your phone the next day, just in case things go pear shaped, this is a weekend thing...

As for your question:

If you are on stock ROM then as i say above, you can only use the 8.43 series. Im back on the earliest one you can now download from Dorimanx, i had trouble with pretty much all the 8.43v8x series, but did test and use the 8.43v92 one for a while, until i made the mistake of trying the later ones: FS1, v99.1, v99, v98, v87, v96.

Computoncio's 8.43v92 was stable for me and others. Your results may vary!

I had issues when i tried to flash the later ones and could never recover and had problems with the new recovery.

Now that im back on the early one it may be some time before you find me flashing a new kernel if at all, Dorimanx is retiring from SGS2 life and its up to the terrible dev twins (cybernetus and computoncio) who we are grateful for for building these kernels (even when they boot loop! :) ) whether they continue to build the kernel from here.

As with many of the things mentioned in my steps above your phone is an individual so it may work with ones that mine didnt.

Generally you can get an idea of whats stable by reading feedback in here....start at the last post and work backwards if youre keen on trying the latest, or use search to find out about a particular version.

I wasnt going to twice in one post, but hey...

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Personally at the moment my biggest problem is with the new recovery, id probably like to see it removed from the package altogether as if youve already got a working recovery set up, theres no reason to overwrite it with another version thats customised and has issues, and anyways in my book each user should be responsible for installing recovery themselves.

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