We previously used this $29.99 IKEA Sniglar changing table to change diapers. You could also buy it for the purpose of two very inexpensive play tables!
If it is already assembled as a diaper changing station, remove the legs using the Allen wrench included from IKEA. Taping this to the bottom of the changing table helps keep it from getting lost.
Remember there are two dowels that help keep the legs on the table. The legs are easily removed by pulling them away from the table.
You will be cutting the top half of the leg off so when reassembled the top of the leg on the shorter (bottom) table is flush with the border of the table. See next two pictures.
Draw a pencil line across to ensure a level cut.
Put on those safety goggles and saw all four legs. You can use any saw made for cutting wood. I happen to be using a electric hand jig-saw. You could use a hacksaw or table saw.
Now you will have 8 rough ends. Get to sanding!
Be sure to sand the edges so little hands don't get hurt.
Reassemble (or assemble for the first time) the legs. Two match each side.
Place the metal cam into hole at underside of table and insert screws.
Tighten all screws with the Allen wrench.
These could be used as train tables, Lego table, sensory table or outside as a sand table. Staple gun a shower curtain to one to use as a water table! Have fun!