I've left all monies from these 3 account to my son.
Assuming that the terms of your living trust are fairly standard, most living trusts allow for the addition and subtraction of funds from the trust without changing the terms of the trust.
This is a general answer only and you should seek the advice of counsel to address facts specific to your circumstances.
It is challenging to answer any specific question about a trust without reading the document. That being said, what you described would not normally require trust changes. You would be well served to consult with a local trust attorney for a review of the trust so that you will better understand how it operates.
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If you are simply adding or removing funds from an account owned by your revocable trust, you shouldn't need to make any changes to the trust.
If you want to talk a little more about this issue, I am an Oklahoma attorney and I am happy to set up a time to talk with you.