10 - 30 minuten
My daughter dropped her phone in the toilet while washing her hands. Fortunately, she'd already flushed!
It took a couple of tries to get the phone back up. The iFixIt guide was great during the take down, and the idea to use an old egg carton to keep the parts separated (something off the web at YouTube) really helped.
I bought the spare battery JIC, and it looks like the old battery was "okay", but better safe than sorry.
The toughest part was getting all the corrosion out of the phone. She had to mail it from school, so it was several days before I cracked it open. The first time I opened the phone it took about 1.5 hours for the tear-down. The second time went much faster :-), at less than 30 minutes.
I'm not sure how this can be done without some sort of magnifier. I've got a head magnifier and highly recommend that for anybody trying to work on a phone.
Also, stick with the Samsung devices. My neighbor dropped her phone in a toilet the same day and I cleaned it up for her after I did the iPhone. It is a much cleaner design as evidenced by the iFixit guides - I really didn't need the guide to work on it. That one came up perfect the first time.
There's now two more "customer" asking for help. I need to start charging for this stuff!