Put the outer races in the freezer: they drop right in. Even better: dry ice.
The inner races: heat them up, they drop right on. Especially if the triple clamp is in the freezer first.
For the lower clamp, you can heat up the aluminum, and pull it off, then pound the bearing down with some heat. Or carefully dremel, then chizel it. The knurled nut bearing can be a little tricky sometimes, but dremel and chizel usually works.