Running with phones = running with scissors (w/o the potential eye issues)
1 - 2 hours
I went for a run with the wife but forgot I wasn't wearing my running shorts with zipper secured pockets. One good trot was all it took to have my phone launch from the pocket and land directly on its display. Fortunately, the concrete slowed the phones descent. Unfortunately, this lead to a destroyed LCD display.
The repair was very easy (Samsung did a beautiful job of designing the phone for replacing the most likely piece to be damaged). I have had my hands in quite a few Icom brand two-way radios and those things aren't nearly as forgiving for the average person to assemble/disassemble.
The guide was great with pictures and steps that would make any technician breeze right through the process.
The only hiccup: the website had an inventory discrepancy where the quantity of blue LCD components was listed at two but turned out to be zero. The customer service rep quickly provided a $10 coupon for my troubles and I decided my phone would be fine being two-toned with white on the front and blue on the back.
As with any instruction manual, read the entire thing before you begin. At the very least know what needs to be done a few steps in advance - it will make the process go more smoothly.