Now it's time to press in the new races. Using the old race as a drift, knock in the new races with a BFH. It's easier if you leave them in the freezer overnight before trying to install. You can see how much more surface area there is on the new taper bearing race than the old ball bearing race:
With a little closer inspection, you'll notice that TLR Junkie made the 'freezer recommendation' when installing the outer races into the frame, NOT when installing the inner races on the stem. Therefore, his recommendation is valid. Freezing the outer races will make them easier to fit into the frame.Putting the races in the freezer makes them tighter, not looser so that is not a good idea. If you have a big freezer you could freeze the entire stem.