A couple of suggestions.
1). If you are over about 40, some sort of hands free magnifier helps a lot - I used a headband mounted jewelers magifier called an Optivisor.
2). A pair of fine tipped tweezers and a gentle touch will let you grab the pressure contact in step 5 without getting skin oil on it.
3). Work over some sort of tray to stop small parts from rolling away.
4). If you don't have a spudger or a set of plastic case opening tools (or you know you have them, but can't recall their exact location at this moment...*cough*), the corner of an an expired credit card, or a stiff guitar pick will work to pry the battery loose. It will likely bend the card though, so do use an expired one. I used an empty Starbucks gift card I found in a junk drawer...