Iphone 6 and Iphone 6S has a same disassembly process.
Tools needed for iPhone 6 disassembly.
Screwdriver.
Suction cup.
Plastic spudger or plastic card.
Links to the necessary tools you can find in description.
Remove two screws on the bottom.
Using a hair dryer, heat the front side.
Fix suction cup near home button.
Pull up the ring of suction cup until gap appearing and you can insert plastic card
there.
Slow and gently detach the display, along the entire perimeter of the iPhone.
Remove two screws and disconnect the battery cable.
Do not use the metal objects to remove it.
Remove four screws and disconnect the LCD connector.
Do not use the metal objects to remove it.
Remove all screws on each side of LCD panel.
Carefully separate "home button" and replace it.