Hi, I'm looking for a replacement nut for a 6 string Squier Stratocaster.

I've been looking online, but I can't seem to find one that's "ready to install" (i.e. only blanks, or ones that require filing).

Anyway, does anyone know where I can find such a part? Thanks
When the power of love overcomes the love of power, the world will know peace. - Jimi Hendrix
If i were you, i would check your local music stores. If you cant find one, then you may be able to use one from an imitation strat.
You can find those everywhere, you just need to look for a pre slotted nut. You're still probably going to have a little sanding and whatnot to get a perfect fit and then a little filing for a proper setup, but they do come pre-slotted.
Skeet UK is awesome, he can get WD Music parts discounted.