3 things:
rear pad is very easy. If you've done the front, you can do the rear. Knock out the pins, remove the retaining clip at the back of the pads, spread the calipers, remove the old pads and put in new ones.

letting the pads wear too much can damage the calipers

Running the car once per week 10 miles at a time doesn't really keep it in good shape. Probably does little more than put condensation in the oil. Drive it further.