I am refactoring a method which is over 500 lines (don't ask me why)

The method basically queries a list of maps from the database and for each map in the list does some computation and adds the value of that computation to the map. There are however too many computations and puts being done that the code has reached over 500 lines already!

Here's a sample preview:

public List<Hashmap> getProductData(...) {
   List<Hashmap> products = productsDao.getProductData(...);
   for (Product product: products) {
       product.put("Volume",new BigDecimanl(product.get("Height")*
              product.get("Width")*product.get("Length"));
      if (some condition here) {
         //20 lines worth of product.put(..,..) 
      } else {
         //20 lines worth of product.put(..,..)
      }
      //3 more if-else statements like the one above
      try {
         product.put(..,..)
      } catch (Exception e) {
         product.put("",..)
      }
      //over 8 more try-catches of the form above
   }

Any ideas on how to go about refactoring this?