Do less. Someone drawing this changing line is being told that the difficulty they face has no cause in them, that it will resolve of itself, and that active intervention is the one thing likely to prolong it. The instruction to use no medicine is the text's own, and it is the rare piece of counsel in this book that asks a querent to sit still while something unpleasant works itself out.
Distinguishing this from ordinary passivity is the whole skill of reading the line. The prescription depends on the trouble being genuinely innocent in origin, and the hexagram has already established, at its third position, what such a trouble looks like: damage arriving from outside and landing on someone who did nothing to attract it. Where a difficulty does have a root in the querent's own conduct, this is not the line describing it.
Central and correctly placed in the upper trigram Qian, this is the ruling position of Wu Wang, which is why its counsel carries the weight it does. The joy promised at the end is not the joy of a cure but of a recovery that arrived on its own, and a reading here is an instruction to make room for that rather than to go looking for something to fix. Patience of this particular kind, applied to a trouble with no root in the querent at all, is what the line asks for, and it is a harder discipline in practice than it sounds on the page.