if i replace the battery on my 2008 rave will i have to have a mechanic do anything to it
Nothing to reset. Not sure on the toyota, but worst case you have to reprogram your radio presets.
Usually, you can get a tech, from wherever you get you battery, to put the battery in for you. If you ask, they might even be willing to help you reset your clock. Unless you suspect that something else is wrong with the car, your mechanic shouldn't even be involved.
Search Toyota RAV4 Questions
Toyota RAV4 Experts