By passing on your genes to the next generation. you will outlive your body as long as your gene line is not lost. If you mean with becoming immortal with your body intact, you could cryogenically freeze your self. with periodic genetic engineering you may be able to last forever as long as there is a way to replace mutating genes with the correct ones. Becoming immortal in anysense of the word will likely not happen with your body intact and functioning beyond genetic engineering.