In your Main Portfolio view, below your highlighted items, there should be a place that says:

Manage Your Portfolio
Bulk item management tools help you manage your portfolio quickly.
Click one of the following four actions to open additional instructions:
Change Ordering || Change Access || Move Items to Folder || Delete

Click on Change Ordering

Once you do this will appear:
To change the ordering of the items in your portfolio,
change the numbers in the ordering fields below.
Highest numbers are displayed First.
Once complete, click the "Reorder" button.

Open the folder you want to reorder, and do the above.

Hope that helps.