The next three steps describe how the reinstall the worm shaft assembly during reassembly.

Partially insert the worm shaft into the bottom of the worm gear housing.

Use pliers to slip the worm thrust bearing and bearing races, in order, over the top of the worm shaft.

The worm thrust bearing should lie in between the bearing races while on the worm shaft.

Slip the upper worm shaft roller bearing onto the worm shaft so it lies on top of the upper bearing race placed previously.