20 - 40 minutes
Replace fan on Mac Mini + front & back display on iPhone 4.
Received part and tools from iFixit 2 days after placing order.
Replacing fan on Mac Mini:
No-brainer and no problems. Time spent: 15 min.
Replacing displays on iPhone4:
Went like at dream thanks to the perfect guides from iFixit. Time spent: 1h30min.
Probably more idiots like me out there who doesn't read the full instruction before starting the work -> Keeping track of all the disassembled part was the biggest challenge.
What I did: Used a dinner plate, tape and marker for parts described in each step.
What I should have done: Print out the readymade sheet provided by iFixit...