Heat is great for removing bearings from shafts, but if it's stuck in a blind hole you have the opposite problem. I've even used freeze spray before, freezing the bearing thoroughly before having a go at it.
If you have, or can borrow, an internal bearing puller and a slide hammer, that's the way to go. There are a few types I've used successfully, the expanding arbor type work well, and there is another type of kit which grips the inner and outer race with clipped ball-shaped inserts.
The shock from the slide hammer normally works a treat.
If you haven't got anything similar, you can improvise something. Make up a slide hammer if you don't have one, then make an implement that will be able to grip on the rear face of the bearing - maybe a piece of scrap round bar, slightly smaller than the shaft diameter, with a slot ground into one side to make a lip to pass through and grip on the rear of the bearing. An 1/8 of an inch lip on a steel bar should be able to pull it out of an aluminium casting.