To expand on what Sushil bhai has already said... most ESCs have no reset button/switch that puts it back in factory settings. The manual does list what are the "default"s for each of the parameters/settings that can be changed via programming; so you have to individually set each of them to the suggested defaults one by one.
BTW, you normally do not have to do any programming on the ESC, they work right out of the box for basic flying. It is good to know about though, and be aware of the options/possibilities