How do I reduce the size of a trade

 
I wish to reduce a trade size from £1.00 to £0.50, how do I do that on MT4 platform.
 
Sandy1946:
I wish to reduce a trade size from £1.00 to £0.50, how do I do that on MT4 platform.
starting position         When you are in the order windows, change the lot

Modif         Volume: 1 --->Volume 0.5 and press "Close"

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