There are now dozens of leading theories, and many of them will get you there. They all share similarities though.
The best thing to do is identify your weaknesses. As a runner, you could create an aerobic profile and work on what needs improvement. A good program will train everything but with more emphasis on what you suck at.
Say you can't run a 3 min km. You also can't run a 72 comfortably. Your first goal should be to comfortably run under 36 for 200s, or under 18 for 100s, or even better under 9 (ideally 8 or 7.5) for 50m. Then build that up so you are able to do 200s, 400s, etc much faster than goal race pace. You can start from the bottom and get your 50m time down and build all the way up to the 400s, eventually to Ks and then the 3k.
While doing that, build mileage and get a good long run in. You can do the 50s or 100s in any run.
Once you have hit the mileage you have time for, it's time to run it faster. Improve your aerobic speed until you plateau. This is the pace at about first ventilatory threshold/ a bit under M pace. I'd say do most of your running at this effort, except the short fast stuff you do often.
Then intro M pace, then T pace, I pace and before you know it you've completed a funnel (where your short 50m time at the beginning and comfortable 3km race pace at the end converge). At that point you are likely only 6 weeks away of KM repeats or whatever interval at RP training from hitting your goal. Over 2 years you could accomplish a funnel like that. But the key would be to never over train, never burn out, and never get injured. If you get injured on 60km a week there's a major issue anyway!
At 60km per week you better do some quick running daily. Like strides, short hill reps, surges in easy runs, etc. Running quickly is a skill.