So, I had a lovely little video made while I assembled one of the units, but it doesn't appear that I can upload it, so I'll just have to write it out instead. Also, the pictures I'm including don't show you the finished product (but you can see that on the images provided by the seller).
The first picture shows where the directions are located: printed on the inside flap of the shipping box. So don't freak out and look through the entire box for the instructions. They're not on a separate piece of paper. However, I doubt you'll need any directions because these items really are self-explanatory.
The second picture shows the two units inside the box. Just take them out and you should get the idea. The top drawer is packed inside its holder, so all you need to do is put the casters (wheels) on one of the black frame pieces (I don't think it matters which), then put the other black frame atop the one with casters, then put the top drawer on, slip the other two plastic drawers in, and you're done. It moves freely and easily, and the drawers slip in and out without any issue. (I was able to demonstrate opening and closing them with one hand while I filmed it.)
Keep in mind, however, that the assembled piece is short. About two feet, I'd say. You might be able to keep the casters off and stack one unit on top of the other if you want something taller, but I don't know how sturdy it would be since I don't know if they're made to stack this way. I bought these to house fabric--mostly remnants and such for smaller projects (quilting, sachets, kids' separates, blouses, etc.). You're absolutely not going to get any fabric inside without folding (unless, of course, you're storing pre-cut squares for quilting, for instance) because the drawers aren't long enough for apparel fabric (and absolutely not home-dec fabric) without folding. Still, I managed to get a lot of fabric into each drawer. (And the weight of the fabric helps to give the units a little more stability when rolling.)
I do recommend these units and intend to buy a couple more because I still have MORE fabric to store!