How to Deflate the Centre Strut on the Cabrinha X Wing?:-)

Does anyone know how to deflate the centre strut on a Cabrinha X Wing as I do not want to break anything (I am all good with everything else?:-)

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randomfoiler said..
unscrew the valve?

Yes I know that but there is a "pinch value" that is well know in kiting circles as I have now found out so all is good but I wonder why do you want to isolate the centre strut from the rest / outside of the wing?, maybe someone knows? & does this mean that the centre strut can be & should be pumped up to a different / higher psi pressure? and why what are the advantages & disadvantages?;-) Many Thanks :-)