Heater Core

[WillyBoy17]

About a few months ago, my roommates heater core went out in his 2000 ram. Took it to Firestone and paid 700 bucks to get it fixed. This morning, I went outside to get something from my truck and there was a pool of coolant in my passenger side door, my heater core has followed suit. Anyone changed a heater core before? I have looked up online how to and saw different things, but I do believe I will not pay 700 bucks to fix it, college salaries are pretty low these days.....