changing spigot?

[littled630]

Ok i bought an igloo 5 gal beverage cooler. I bought a new better control spigot from my LHBS. Problem is the old spigot is 13/16" diameter threads and the new one is 1" diameter threads. Any ideas how i could resize this hole without wrecking my cooler or ruining the circle shape? I thought of a dremel tool with sanding wheel but ill never keep it a perfect circle. Also cant use a paddle bit or hole saw due to the existing 13/16" hole.

 

[littled630]

Heres an image of old spigot(left) and new spigot(right) and the existing hole in the cooler.

 

[blaster_54738]

Step Bit

 

[littled630]

Yeaj thats what i was afraid of cause that means buying an expensive tool that i dont have access to for free lol

 

[blaster_54738]

if you have a harbor freight near you, you can get the bigger ones there at a halfway decent price. it'll go through the plastic real easy. I've actually used my HF bits to drill through a couple stainless pots and to put a sight glass on my keggle. i've definitely gotten my monies worth out of them