Heat the case and use a drift pin from the top to tap it out. You will need to replace it, but it's a standard needle bearing size. The upper one is a bit trickier. Its also readily available. I used a very small cutter on my porting tool cut the race then pulled it out. I then cleaned up the case with a ream. Unless you feel really comfortable doing this and have the tools I suggest blocking things off then clean the bearings real well after vapor blasting. It's not the most critical bearing on the bike.