I have always done a 3 week IM taper. Cut volume by 1/3 1st week, and other 1/3 the 2nd week, and to about nothing other than loosening up the 3rd week (and packing, traveling, etc). When i cut the volume I also increase the intensity but not to the point of residual soreness. Remember to also reduce your caloric intake so that your are not “fat” on race day. Eat good and healthy and drink a lot! Have fun - positive attitude makes you faster!