How do you size a watch band and replace a watch battery?

I have a job interview tomorrow at a small-repairs shop. They told me that my main job there would be sizing watch bands and replacing watch batteries. Now, they said that it would be a “hands-on” interview in which they would show me how to do this stuff, have me try it, then determine how good I am at it.

I am very good with my hands and have been building models and repairing things for as long as I can remember. I’ve never had any occasion to fix a watch or even replace its battery before. I want to know at least a little something about this before I go in for the interview, even though they said they’d show me. Does anyone here have any advice?

Some info on watch band sizes here.

Some common watch band adustment methods include:
Non-stretch bands

  1. small screws (think eyeglass screws)- simply remove the screw(s), take out or add links, replace the screw(s).
  2. spring loaded pins - remove a pin (usually from the clasp), replace pin in a different hole.
    Stretch bands
  3. U shaped metal joiners - bend up the tabs on either edge of the band, remove the joiners, remove or add links, replace the joiners, bend down the tabs. Look at the edge of a stretch band and you’ll see what I mean.

Common watch battery replacement methods include:

  1. pop off backs - there will generally be a tab or slot along the edge of the watch back where a prying tool can be inserted. The back is popped off, the battery replaced, and the back popped back on. Replacing the watch back may require the use of a special tool that resembles oversized, padded pliers.
  2. Screw off back - these generally have evenly spaced notches around the edge of the watch back. A adjustable two-pronged tool is needed. Adjust the prongs so that they fit in opposing notches on the watch back. Twist the tool to unscrew the back, replace the battery, screw on and tighten the watch back.

Some watch batteries are held in place by the watch back itself, some are held in by a small screw and tab. Once you are in the watch it’s easy to see what you need to do to remove the battery. Also, most water proof/water resistant watches have a rubber O-ring seal. It is extremely important that the seal be properly seated before replacing the watch back. The O-ring makes pop on watch backs much more difficult to re-install properly.

You’ll probably see ather types of band adjusters and battery replacement methods, but this should get you started.