'96-'98s require the special reset tool. You can buy it from IPD, although I've seen the same tool from other sources for less. Still more than $100. All things considered I figure it might be "worth" if if you have two or more cars in the affected years. Otherwise it makes more sense to me to have my dealer or Volvo shop do the oil changes and reset the light.

You can always just ignore it, it goes off by itself in a couple of minutes. (unlike the stupid BRIGHT Honda light that just comes on and stays on when the counter tells it, like when you're driving along a dark highway at night.)

Alternatives include taking the bulb out and a square of black 3M electrical tape ($1.35, Home Depot or Lowes). (The tape also works well on "check engine" lights, etc!)

-bill d cat