How and where to replace your old, depreciated iPhone battery

How and where to replace your old, depreciated iPhone battery  The Verge What I hate most about Apple slowing down iPhones with bad batteries  BGR How to: Check iPhone battery health, DIY replace, and speed up performance  9to5Mac iPhone Performance and Battery Age - Geekbench  Geekbench Apple addresses why people are saying their iPhones with older batteries are running 'slower'  TechCrunchFull coverage