How do i remove the tethered jailbreak on my ipad?

i jailbroke my ipad firmware 4.3 with a tethered jailbreak using redsnow. i want to remove the tethered jail break and update my ipad to the 4.3.3 firmware so i can jailbreak it with a untethered. how do i removed the tethered jailbreak software?? someone help me!!