You can't completely change the soil. Here is what I would do. Not saying it's the best answer so do some reading too. You'll need a pot bigger than the one you have it in now. Prep it with soil in the bottom. Let the soil in your current pot dry out a bit. Not completely, but about 1/2 way. Gently tap the sides with a hammer or other weighty object. Tip it upside down supporting the soil at the top with the flat of your hand. Slide the pot off. allow any loose soil to fall away with a GENTLE shake. Don't try to remove soil from roots. Replant. The roots will find the new soil and the new soil will buffer the hot stuf. It should help considerably.