10 - 30 minuten
Inherited iPhone 4s from my wife - she upgraded to a new phone because weak battery and wifi not working. At that point I thought "what's there to lose, let's fix it"
The repair went fine, about 2.5 hours from start to finish. As others here have reported the wifi antenna could probably be replaced without taking the logic board out - but for a first-timer that would be even trickier. All repair steps went fine. Battery life much improved but even after resetting and restoring the phone no wifi or bluetooth. Double-checked connections. Problem must be somewhere else.
Good work light. Work on a white surface. At every step put the little screws somewhere where you can separate them and mark each one - an egg carton was suggested here. Don't take too long of a break between disassembly and putting everything back together. Makes it easier to remember.