How can i get rid of pimple scars? how to reduce its redness

Improve, not remove: Scars are permanent. Having said that, there are ways to make them less noticeable. The first is time: scars mature over 6-18 months and don't assume their final form till then. Other methods are pressure, silicone sheeting, mederma, steroid injections or surgery. Surgery is a last resort for most scars, but many can be improved in this way if all else fails.