Trans flushes at shops/dealer usually run ~125-175.
You can get a filter and gasket on Rockauto pretty cheap and buy about 10 quarts of ATF locally.
Dropping the pan will let you change the filter and clean the magnet and the general buildup of material in the pan. That will get you 40-60% of the fluid. Refill it and drive it for a few days or a week or two then repeat.
This will get another 40-60%, granted it will have mixed with the older fluid, and is not as efficient as pulling the line, but if you're not comfortable pulling the line or doing that way, this way offers an alternative.
Checking the fluid level in these sucks too, the dipstick arrangement is not ideal.
2014 Focus SE Manual -
2006 Focus ZX4 SE Auto -commuter 110k /traded