Help with idler pulley

[exbass94]

1994 Explorer 4.0 OHV.

I'm trying to replace the idler pulley. I took the old pulley off, but cannot remove the bolt from the pulley. It is held in by some type of lock washer on the back side of the pulley. It is apparently to prevent the CCW-spinning pulley from making the bolt back out.
1. What's the easiest way of getting this thing off?
2. Can I reuse the washer?
If no, what is the exact size replacement I'll need? (I need to take this apart, swap the parts, and reinstall all at once. I can't be searching hardware stores for the correct size. I can't afford any downtime on this vehicle!)

 

[exbass94]

bump.... no one has ever replaced an idler pulley before??

 

[np24]

that little washer is only to hold the bolt in while ford installed on your engine.
its not needed, but you can reuse it is if you want.
you should be able to grab it with pliers and unscrew the bolt.
or just break it off with a screwdriver.