Letting go of problems means not classifying something in your life as a problem, any more. Make a list of problems you have, and then just decide which ones are things you don't really have to worry about. Don't try to eliminate all of them in one day, just decide on one, for today, that you will let go of. For example, I could worry about many things, including:
*Not making enough money
*Owing too much on credit card
*Whether my book gets accepted by Routledge.
*Whether I can learn piano good enough to play in public.
*Whether I am a good poet.
Now I might be socially awkward, but I have enough friends who I don't have to worry about being awkward with, so I don't have to worry too much. So I could just renounce that as a problem. It doesn't mean I am socially suave, all of a sudden, but that I just don't care as much. Not caring actually makes it easier, because 90% of the awkwardness is in caring too much about being smooth or not. Wise people care more about whether you are kind and polite, more than if every move you have is smooth as silk.
Many people are more socially adept than I am, and many others are less so. It could be something to work on, but it is not going to be an existential problem I need to lose sleep over. If people see me as awkward, then it might be good for them: they can feel that they are less awkward than me and feel better about themselves. That would be great. If they see me as not awkward, then there is no problem. I am helping them to be less awkward, maybe, so either way it turns out great for everyone.
Many of my friends and relations are older people, older than me. One thing you can do as you age, gracefully or not, is to not worry any longer about certain things that might have troubled you earlier. But you can start the process of not worrying about shit at any age.
Think of a problem that troubled you in youth, but that now you think of as trivial. Now see if your older, wiser self would tell you the same thing about a problem you have now.
You can also take your biggest problem. You don't have to release it yet, but decide what your biggest problem is. I've found that if something is a BIG problem, it is part of your identity, in a way. It is something that would cost you a great deal to release, because you would be giving something up, some illusion necessary for your sense of self. You must be aware that you are giving something up by releasing the problem. So by all means treasure and appreciate your problem if it is important to you.
If I am not a good poet, then I am a fraud, I might think. So I have to keep that as a problem for myself: to prove to myself or others that my work is good, that I have some underlying talent. If I embrace my poetic mediocrity, though, then the problem is no longer there. Or rather, it becomes a wholly different sort of problem: how to write better. That is amenable to many avenues of approach. I can have fun and write different kinds of poems, and really never have another bad moment as a poet, just as I never have a bad moment playing the piano, even when playing badly. What I've given up is the idea of myself as a poetic genius, but this seems faintly risible in retrospect, though it was a part of my self-concept even in negative form.