Use a heat gun and a pair of large channel lock pliers (to hold the engine). Strip the engine down completely, to block-and-bearings only, then heat up the block as hot as you can get it (while holding with the pliers). Then tap the pliers (with the engine in it) so the bearing will fall out of the block. Flip over, and do the inner bearing. Re-insert the inner bearing first, then the outter bearing, heating between inserts.
Hope that helps.