We recently took a glacier walk, my adopted daughter and I. It was well organized. The driver contacted us the night before and in the morning kept us informed before he came. He set up our lunch on the way out, was a safe driver, and very courteous. We ended up getting a guide for just the two of us near the glacier as the both of us could not keep up with the youngsters. Was a very informative and fun trip. It will be roughly a 2 mile round trip if you just want to get on the glacier; otherwise more likely to be 4 miles, which may be a bit much if you're older or have foot/leg/knee issues, as both of us did.
Rather than crampons, the center at the glacier uses microspikes, which are easier to get on and off and work well.