Hi, assuming the timeline is not turned off and you're not in Direct Modeling/Base feature mode, this is how I edit sketch offsets. In the browser on the left side of the screen, you should find the sketch under Sketches, and be sure the lightbulb is turned on for visibility. Then you can right click the sketch and choose edit. Since to my knowledge you can't go back to the original offset action to change the offset distance, what I do is just use the good old Sketch dimension tool under the Sketch tab, and individually dimension the desired distance between each offset section. A really powerful trick is after you add a dimension to the first section (click one line, then offset line to place dimension), be sure the dimension is editable (double click it when in select mode), hover over the dimension area, and you should see something like "d2, Dimension value" (if not be sure 'Show tooltips' is on in preferences). Your dimension will likely be something other than d2. Then when you make the next dimension, instead of a numerical value, just enter that previous label, in my case d2. Continue this for all your sections, and then when you change the original dimension (d2 in my case) they will all update.
When you exit the sketch the revolve body should update.
Perhaps a more simple feature would be good.
Hope that helps a little and let me know if something wasn't clear.
Jesse