Here is a simple tutorial with screenshots on how to copy file from Ubisoft to Steam.
How To Transfer the Game From Ubisoft to Steam
Step 1
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Step 2
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Step 3
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Step 4
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Step 5
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Step 6
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Step 7
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Step 8
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Step 9
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You forgot to mention you need to spend another 50 quid for the game + WoNY to be able to start the download in order to verify the files?