IPhone 8 battery replacement.

 Before you start, discharge the iPhone under 25%. A charged battery could catch fire or explode, if accidentally infringed. 

• Turn off your iPhone.

 Opening the iPhone 8 will compromise its waterproof seals. If you do not replace them, the device will be functional, but no longer waterproof. 

• Remove the two 3,5 mm pentalobe screws located at the bottom of your iPhone
   

 Warming up will help you cut through the remaining adhesive, which secures the display, allowing for easier opening. 

• Use a hairdryer to warm up the lower half of the display, just above the home button.

 Makes sure that the suction cup does not cover the home button, as this as this will prevent a seal from forming. 

• Pull the suction cup to create a small gap between the display and the rare cover. 
• Insert a pick into the gap. 

 The watertight adhesive, which secures the display at place, is very strong and creating this little gap requires a significant amount of force. If necessary, loosen the display by an upwards-downwards movement, to create enough room for the spudger. 

• Move the pick gently to the left along the bottom edge of the iPhone. Gently tilt the pick, to gradually enlarge the gap. 
• Move the pick to the left side of the iPhone, by an upwards-downwards movement, all the way to the volume buttons. 

 Do not move it all the way to the top side of the display, as this may damage the plastic clips which secure the display.

• Move to the right side of the device with a same movement as before to separate the display from the cover. 

 Do not slide the pick too deep inside, this could damage the display cables which are located on this side of the device. Slide it it, maximum, to the width of the display frame. 

Use the suction cup to lift the display and open the device. 

 Do not lift it into more than a 15° angle, as this part is still connected to the cover by thin flat cables, that could easily get damaged. 

Remove the suction cup.

Insert a pick into the gap on the upper side of the device to cut the remaining adhesive. 

 Be careful, not to damage the plastic clips on the edge of the phone.

• Gently pull the already opened display downwards, to disengage it from the clips on the top of the device. 
• Open the iPhone by flipping the display to the right, as when opening a book.

 Do not try to completely separate the display from the rare cover, as it is still connected by fragile cables.

• Remove the four Philips screws, which secure the lower display cable bracket
• two 1,3 mm screws
• two 2,8 screws

 Make sure that when re-assembling the phone, you use the correct screws and return them to their prior place to avoid damaging the device.

• Remove the display cable bracket
   

• Use the tip of the spudger to lift the battery connector from its place on the motherboard. 

 Bend the connector cable outside of the device, to avoid electrical contact with other parts.

 Before you continue, make sure that the battery is disconnected. 

• Use a spudger and disconnect the lower display connectors by prying them up from the motherboard. 

  When re-connecting the cables, press down on their edges until you hear them click back. Do not press down in the middle, as this could permanently damage them. If you see any white lines on the display, or notice lack of touch response, make sure that this cable is properly connected.

• Remove the three 1,3 mm Philips screws which secure the front panel connector bracket. Remove the bracket. Disconnect the connector from its place on the motherboard and remove from the phone.

 This connector should likewise be re-connected on the edges, to avoid damaging it. 

• Remove the display part.
   

 IPhone 8 battery is secure by 4 double-sided adhesive tapes – two on the top of the battery and two at the bottom.

Each tape has a black ending, stuck on the top of the battery, so you can recognize it easily. 

Remove the ending of the first tape, which is located at the bottom right side of the battery. 

 Use round tweezers or fingernails, to avoid damaging the battery.

• Pull out the tape a little bit, and wrap it around the ends of the tweezers.

 It is easiest to remove the tape first by pulling it out with fingers, and after you managed to pull out a large enough part of it, wrap it around the ends of the tweezers.

 Hold the tapes straightened while pulling them out, and make sure they do not twist. If they stick onto something or to themselves, they might rip. 

• Pull the ending of the tape with the tweezers, and pull it out from the bottom of the battery towards the bottom of the iPhone.
• Pull gently and consistently, until the tapes are completely removed from under the battery. Pull them out in a maximum 60° degree angle, or even less.

 The tapes have a tendency to return to their original length. If it slips through your fingers, just get hold of it and continue pulling. 

• Repeat the process for the remaining 3 tapes.
• When removing the last tape, hold the battery down to avoid it from popping out under pressure. 
• If you managed to remove all of the tapes, skip to the next step. 
   

• Remove the battery from the phone. Adhere new double-sided adhesive tapes onto the new battery.

 Install it into the phone by following the steps in reversed order.