It means reset your work set weights 5%. Let's say you were stuck at 300, you'd reset to 285 for your working weight. So you'd do 285x5x3 on Monday, and then Wednesday would be 2 sets of 5 at 80% of that weight, so 230. Friday you'd do 290x5x3. The following Monday is 295x5x3, Wednesday is 235x5x2, and Friday is 300x5x3, and so on and so forth.