Even after individual's name, the time of death, and death condition on the Death Note were filled out, the time and condition of death can be latered as many times as you want, as long as it is changed withing 6 minutes and 40 seconds from the time it was filled in. But, of course, this is only possible before the the victim dies.

Whenever you want to change anything written on the Death Note within 6 minutes and 40 seoconds after you wrote, you ust first rule out the characters you want to erase with two straight lines.