Open the instructions and spread them in your work area. If you are assembling a second-hand crib, then a have a photo of the model on hand to check against while you are working.
Place the four sides of the crib on the floor. If you have a model with drop down sides, you can identify this part by the hinges and/or grooves that will be attached to the ends.
Attach the legs to the four corners of the crib. This is where the electric screwdriver comes in handy as the legs need to be firmly attached to make the crib stable.
Locate the swivel casters and locks on the side pieces. The swivel casters fit into the holes on the side pieces.
Using a Phillips screwdriver, attach a screw to the corresponding hole (short side to long side) on the crib pieces for each castor. Tighten until the castor clicks and locks the side into place. Carry out this task at each corner until you have a frame for the crib. For drop sided cribs, you will only assemble three sides.
Lower the mattress support into the frame. Using a flat head screwdriver attach the frame at each corner of the crib. Add the mattress and bedding.