Depending on what fuse, but on the left side of the dash, when you open the driver door, is a lift off panel that will expose your fuses.
You can use the factory approved method with a $125.00 wiring part.
Another possibility is the $25.00 part at any auto store the wiring converter , but this may interfere with the computer system in the chreokee. It's you choise
here is a link for more info
"PTC" is the standard abbreviation for Positive Temp. Coefficient Fuse. They are often resetable.
(Q) Is this to upgrade the factory radio/stereo?
If Yes, I was in the same position. And I went and purchased the stereo first. The dealership offered kits, and they ask make/model and year of the car. I was able to choose from two different kits, that basically handle the wire-mapping of the 2000 elantra, automagically. I got my new stereo installed, and have been happy with it ever since. Hope that helps.