I followed the very detailed instructions and the "difficult" battery replacement went very well. Everything seemed fine until I tried using my laptop in my lap. Then I found that it repeated crashed when I moved my wrist on top of it! Looking at it more closely revealed the battery connector was missing some solder on some wires! I soldered them down and now it seems to be working fine. (You can see in the photo that 2 wires don't look soldered at all.)