How to reverse mold stock
Step 1: Goto T-code MB51 - Add mold name and plant, click execute
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step 2: Copy Material Document number ( Movement type 561)
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Step 3: Goto MIGO
Step 4: select Cancellation and then Material document in the adjacent field and paste the copied material document number(red highlight)
and click execute 
Step 5: Then click ITEM OK
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Step 6: Double check the mold number and plant
Step 7: SAVE
Verification
Goto MM02
Go into the mold
Click on view Plant stock
The value should be zero