Dieting/Fitness advice?!

Dieting/Fitness advice?

I'm in decent shape now but I'm trying to get myself in climbing shape. (I climb during the winter) I want to firm up my abs they are a little soft right now, and strengthen my arms. Basically work my core. My legs are in great shape.

I have a couple questions, I keep being told that if I increase my work out, and skip dinner every night that I will firm up really quickly. And I've also been told when I go to do my morning exercise don't eat anything, eat after I'm done? (I do a yoga warm up every morning & hike a mountain in the morning 5 days a week its about 5 miles). I also do yoga at night, before I go to bed. I have two months to get into climbing shape, I have new partners this year that climb at a higher level then me, so I want to be able to up my game. Do I need to change my workout or change when I eat? If so what should I do?

I do not see any weight training for endurance, that's sets of 15-20 reps with the heaviest weight you can handle.
Do not eat before working out and rather than skip a meal eat smaller ones more often.
You time period is too short if your going too change intensity or style start sooner next time.