The trick is to take a moment and pause and *actually* relax your whole body. Don’t keep continually trying to force it. Think of it as there being a short gap where you let go of all tension, let go of trying to say the word at all, and just allow a moment of silence. It’s quite tricky to get the hang of this, since your instinct is to keep putting more and more effort in, and the feeling of time pressure can be immense. But keep practicing and you’ll get the hang of it eventually. You have to realize that the effort itself is what is making the block so severe. You think more effort will help (as it does it most areas of life…) but in this case, more effort just makes it worse.