Why is it so wet? Can you repot it in fresh compost? If you leave it, the roots are likely to rot.

You've obviously seriously overwatered it, or you have it in a pot with no drainage holes. Either way as Spritz. says you need to repot it in fresh compost and, if the pot you are using has no drainage holes, a different pot. Ideally a pieris should be planted in the ground.

If its in a pot with no holes, then you need to make holes or repot into something that does have holes, as the others say.

In the meantime, lay the pot on its side and raise the bottom, so the top part is the lowest point - leave it like that till the water has stopped dripping from the pot, so a day or so.