1)Make a copy of explorer.exe and rename it to explorer2.exe. (same location as explorer.exe)
2)Edit explorer2.exe as you see fit.
2)Go into task manager, under processes and End Process explorer.exe (leave taskMan up)
3)In taskMan click File->New Task (Run...)
4)type in explorer2.exe and click ok (in create new task window)
The modified version of explorer will be running now. You can create as many different versions of explorer as you want and hotSwap between them without rebooting or using a boot disk. No need to disable File Protection using this method either.
Been along time since I played with this but it may even be possible to rename a explorer3.exe to explorer.exe once you are running explorer2.exe. Not sure if any of the servicePacks look to see if explorer.exe has been altered. (just make sure you have an original backUP) Come to think of it now that explorer.exe is not running you should be able to alter it directly. Then kill 2 and go back to 1.
I found it best just to leave Explorer.exe alone and just hot swap between them so there is no need for extra worry. takes no longer than 5 seconds to hot swap Explorers.
P.S. You can tell when you killed explorer.exe when the taskBar disappears. For instance if you change the start button to end on explorer2.exe. When you run Explorer2.exe the start button would now say end.
It has worked this way in the past!