Step: 

1. Click "Product".
2. Click "Stock List".
3. Select the category that you want to manage.
4. You can make any change in the red box of  "Model" , "Weight" , "Price" , "Stock".
   (Number of stock can be change by add(+) or minus(-).)
5. When you finish, press "update".

must read: If the product no long valid , pls make sure the stock qyt =0 or u can directly delete the product (don't just change the status to red becuase if u do so , if the product already in the buyer cart he/she still can check out)

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Other batch updates functions:
batch update prodcuts' catagory 

Action:

1. Select product that you want to manage.
2. Select action you want to do.
3. If you choose to copy or move, select the categoey that you want it to be.