How do I save space: Does "Trimming" a wav work?

Hello all!  Long time since I've been here.  

Ok, so I've been recording long sets of my worship team.  Meaning give or take 40 minutes of 12-16 tracks. The recording usually goes fine so no issues there.  My issue is that after all is said and done with mixing, I only end up with about 15 minutes of "usable" audio.  That's all the audio I want to use.  So the question is this, how can I "trim" the wav files so that all of the slip editing gets completely removed and each 40 minute wav file turns into a 15 min wav and therefore takes up less than half the space of the original file? So instead of the file being 250mb, it's only 125mb, give or take.

Is this possible?  I know that hard drive space is relatively cheap and that's an option, but, I'm recording every week and all these files are gonna add up real soon and I was hoping there's a way to trim or whatever you call it so that the files although initially big, are able to be reduced to a manageable size.

Thanks for listening!

Will

yeah, that should do it.  Thanks!  Not sure why I didn't think of that.  That's what this forum is all about!  Thanks again!

Will

yes, - I have my audio on an external drive, but what I just realized is that it's recreating the wav files onto the C: drive - ugh!  I don't want that.  I want all the wavs on my external!

I would advise against trying to save space. Get a new HD if needed or an external one and save the old project to it. You never know when or if you will want the old files. I know you are thinking its not good stuff but you could chop it up and use it very differently. You just never know.