I have a 2001 Manual prelude and it recently started grinding when shifting into 2nd at redline. It's only happened three times. Is there a way I can fix the problem before it gets too bad or is it already too far gone and I need to do a rebuild on the tranny?

 

Try replacing the fluid with Synchromesh or equivalent. Otherwise, once they start grinding the damage is already done and it will only get worse going forward.