Hi all, I am replacing a nonworking rheostat for the fan on my Hearthstone Clydesdale. I have the part, and have the stove opened up, but I have a question about the wire connectors. They look like this: I have never seen these before. Do I just pull them apart, take the old wires out, put the new ones in, and re-use them? Tried that, but they were very resistant to coming apart. Or do I need to cut the wires off them and get new ones? Or can I use the usual wire connectors that look like a toothpaste tube cap? (I will get the heat-resistant ones). Thank you in advance!