Letting go of Sentimental clothing

Hello everyone. I've been working for a couple of years on becoming more minimalist. A lot of things are easy to let go of. But, I've always struggled with clothing. I have t-shirts from years ago that remind me of happy or fun times, or they're cute or funny or whatever. How do you let go of some of this stuff? My closet is so full and I only wear maybe 1/3 of it. Thank you in advance for any advice you may have.

Also, not sure if my flair is correct.