where did you read .7 quarts figure? as far as I know all their diffs are listed at 1.1 liters which I think is more than .7 quarts.

I've only seen drain and fill plugs with no washer.

Drain and fill plugs are easy to locate on their respective sides, remember - open the fill plug first, and the fluid should fill to level with the drain hole. Stick a finger in their to feel the fluid level. Fill to fluid run out the drain hole.

This is what I do and have found on my car, I have done my rear diff three times and never had a problem