Wesley, this is the guide for the iPhone 4, not the 4S. The two are distinctly different.

There's no multiple-variants of either model to best of my knowledge (having repaired hundreds of both the 4 and 4S)

Shouldn't there be a disconnect-battery step, before attempting to remove the screen cable hold-down panel?

Warm it up a bit with a heatgun, makes the bonding adhesive a bit softer and you can then lift it up safely with a spudger.

I recommend that steps 20 and 21 are swapped. It's much easier to remove the wifi antenna flex from the board using the blue spudger if the board/PCB is still secured with the 4.8mm screw.

Removing the screw first makes the PCB move up too much when you're trying to detach the wifi flex and can lead to mishaps.

Please, Please, PLEASE avoid using probing elements to try remove batteries. I have had dozens handed in to me with punctures and two that actually started smoking due to people trying to prise the battery out. DO NOT DO IT.

The best way I have found to remove the battery is this process;

1) Try remove it with the pull tab directly, some will come out, some will not. Do NOT use excessive pull force else it'll deform the battery and reduce the capacity.

2) If the pull test didn't work, then get a hot air gun on medium and warm up the area around the battery for about 30 seconds, focusing on the perimeter of the battery. If you see ANY popcorn'ing then you're too hot, you don't want to cook the battery.

2.1) Wait about 30 seconds for the heat to now wick underneath the battery to soften the adhesive.

2.2) Now try pull the battery up, the extra heat should have softened the glue that you can remove the battery without excessive force and without sticking objects under the battery.

Couple of ways to get rounded-out-head screws;

1) use a tiny drop of super glue on the top place your screwdriver on the drop/screw, then sprinkle a bit of bicarb-soda on to the wet super glue, it'll harden very rapidly and form a fillet; wait a minute and you should be able to then unscrew the screw.

Be VERY CAREFUL when doing this, because you don't want to have superglue wicking between the screw and the circuit board.

Perhaps practice on some other things first.

I've removed several like this before; frequently I find the culprits for rounded out slots are ham-fisted people trying to do their own repairs in the past.

Do NOT use a spudger or similar type of prising tool to try lift up the battery. Instead, just warm up the whole area with a hot air gun or hair drier to soften the glue.

The reason why I say don't use an implement to try lift the battery is because far too many times I've seen punctured & bent batteries come in to this workshop that have to be thrown out for safety reasons. It only takes a grain of sand, or a burr on the spudger and you're risking a potential cell rupture and potential fire.

Just use a bit of heat ( not a lot! ) to soften up the glue and it'll come away with the plastic pull tab.

It sits between the logic board top-edge and the two ribbon leads from the screen. Its purpose is to stop the PCB cutting in to the FPC leads over time due to vibrations. If you require I can send a photo.