To be able to unpack objects from a box you have bought or been given you first need to be in a location that will allow you to 'rez' the box. You can tell if this is the case by looking at the menu bar of the Second Life viewer. Just before your location information check to see that there is NO
box inside a red circle. If there is not then you can Build or rez objects there. Many shops will allow you to rez items you have bought or will have an area set aside to do so.

Next, find the item you wish to unpack in your inventory. Often the object will be found in your Objects folder inside Inventory folder.

1) Drag it from the inventory onto the ground near your avatar using the left mouse button,
2) Right click on the object and choose Open from the pie menu,
3 ) Check what is in the box and then choose Copy to Inventory or Copy and Wear at the bottom of the window. In both cases the items insode will be moved into your Inventory
4) Check in your Inventory that the items are where you would like them to be,
5) Tidy up after yourself, using right click and on the pie menu "Take" or "More>Delete"!

NOTE: If you only bought part of an outfit DO NOT choose Copy and Wear - you will end up wearing only that item!!