[onewhippedpuppy]

10 minutes tops. You always have to drain the system via drain plug. After that point you close the plug, hook up the Air Lift which will suck out the residual fluid before pulling a vacuum, close the valve to insure the vacuum holds and you don't have any leaks, and then suck in the new fluid until the vacuum is back to ambient. At that point you are done, period, no bleeding or other work.

The manual way typically works fine, I did it for years. But this is faster and easier, and gets the job done right the first time. As I get older and have less free time, that's worth buying a $100 tool. Which I have used a LOT because it's universal, I'll probably be doing my F150 this weekend as it has 75k on the original coolant.