Grab Dop-Mii Wiibrew Edition and update to the desired System Menu, by going this route you will not be required to redo any of your soft mods
I've done this on a friends wii and mine as well.
Use IOS58+ARHBOOT which is direct hardware access so you dont need to use any patched IOS unless you want to. This is alot easier and if you dont have IOS58 you can use Dop-Mii Wiibrew Edition to install it.
The cool thing about updating this way is it will let you know if you have the correct IOS installed to run that System Menu and ask if you would like to install it.
It will also ask if you would like to preserve Priiloader if you have it installed and ask if you would like to restore it afterward
though it's still recommended to reinstall it.
Don't bother updating Boot2 it's pointless and offers no benefit.
So pretty much this is a great app that will allow you to update w/o redoing anything
just the files off www.filetrip.net
if you want to update your cIOS you can do so as well.
An easy way to update your IOS below 200 non custom ones is to grab a nifty little app called PimpMyWii i believe 2.11 is the latest version and run the app selecting Manuel Install and it will check all your IOS for any out of date and you go through the list selecting any one that you may want to update
hope this helps with the extra info.
P.S. if you have a great network install use Dop-Mii Wiibrew Edition online installation for updating the System Menu it's not recommend but only takes 3mins depending if you have a 10mb connection or just grab the system menu wad off NUS.