Adventuring requires gear- lots and lots of gear. Moving all that stuff around can be difficult, so make things easier on your figures with this handcart.
You'll need one each of the body, handle, wheelSupportLeft and wheelSupportRight files, and two of the wheels.
See the exploded view to see how all the pieces fit together. You may need to clean out the holes in the body a bit to allow the handle and wheel supports to snap in. They will likely be a bit loose at first- that's intentional. Once you have them in, apply a drop of superglue and let it soak in via capillary action. That should result in a nice, solid bond and a sturdy handcart.
Be sure to clean out the hole in the wheels before snapping them onto the supports- it's very easy to snap off the axel when putting the wheel onto the support. For best results, apply gentle pressure while rotating the wheel, in effect screwing it onto the shaft. There's a very slight nub at the tip of the axel that will hold the wheel on once it's attached, so be gentle working the wheel over that.