I looked up the location of the power steering pump for a 1962 Impala in the "Motors Auto Repair Manual" for 1965 and earlier Chevy models.
According to that book and other publications, the 1965 Impala (28th edition) as well as the 1962, has a section about how to repair the pumps. The pump is mounted on the left bank under the generator. There is a little access cap, much like a radiator cap, and you can access it through the V belt that turns the generator.
The older models had the steering pump attached to the back of the generator but in the 60s the pump was mounted separately and had its own pulley and V belt system.
As always, if you are unsure of what you are doing, take your vehicle to a certified technician who is familiar with older vehicles and they should be able to help you.