You're going to need to increase your power. A lot. You'll need to be able to sustain 220–240 W for the duration. Check out this calculator. Your weight won't make a big difference in the final result.

I think the typical recommendation would be to ride long intervals (8–20 minutes) around your threshold (90–105% FTP) with 3–4 minutes recovery between intervals. One of my typical workouts is 4 × 10 min @ 105% and it's really tough. For me, at least.