Anyone know how hard it is to replace the front fuel injector? ..not sure if it is the "o" ring or the injector itself, but it has a very small leak which can be detected when I run the AC and I need to pass inspection in less than a month! Is this hard to replace? It looks easy enough, but looks can be deceiving. Anyone who reads this and has experience with the fuel injectors, please reply a.s.a.p. The more details, the better!