Blockchain records are forever unchangeable

A transaction recorded to the blockchain is permanent. After the next fellow records their transaction onto the blockchain, yours has become immutable. To change yours, you have to undo theirs, and not only is that not happening, but the third and fourth and soon lots and many others will also have to be undone in order to change yours.

Once it's in the chain, it's not that nothing can undo it, but that heaven and earth would have to move, and the agreement of a large and growing group of many grumpy others, would have to be negotiated and orchestrated in order to undo it. So no, give it up, it just ain't happening.