Not pressed on they are rusted on, you have to get the lock collar to move and in some cases the only way is with a bearing puller that hooks in between the collar and the bearing. You may get it to move with a cold chisel by trying to split it through the grub screw hole, this will start to expand it but it means you would need to get new ones. Lift the motor off again and tip the mower upside down, easier to work on
