8 minute mile???

So I've been looking into increasing my pace for a 5k. Here is my problem, I don't particularly like the long run days. But it's inevitable right? If you're going to train properly and actually improve I guess it is.
I found this training schedule online (amongst others) and I really like it. Challenging, but could it be possible? It's worth a try. Worst case scenario I still decrease my time.

12 x .25 miles resting 30 seconds between dropping to 15 seconds
6 x .50 miles resting 1 minute between each gradually decreasing recovery time
3 x 1 mile repeats resting 1 minute and gradually decreasing
.25 mile repeats with a float – run 2 to 4 miles alternating between .25 pace and 200 meter threshold pace. this one confuses me...
Lactate builders – alternate sprinting 30 seconds and 30 seconds at easy pace
3 x .24/.5/.25 run at sprint .25 then slow to 5k pace for .5 then speeding up for another .25 no recovery between distances but 5 mins recovery between each set
5k long run
4 miles at easy pace, then .5 mile at 5k pace then easy for 4 more miles, then .5 mile at 5k, then slow to easy for 2 miles. Finish 12 mile run with 1 mile at 5k goal pace.

Crazy?

*7.5 for 8 minute mile pace... hmmm. almost anyone at the gym can run a 30 minute 5k... but wouldn't it be cool to get it down to 25 minutes!? yeeeah!