It seems that assembling an office chair according to the included instructions is always an impossible feat. They are poorly written and usually hard to understand. However, with a little organization and a wrench, you can assemble your office chair without having to worry about the terrible instructions.
Remove all the parts from the kit box, and remove all plastic covers from the parts. Separate and organize the different pieces of the chair, so you can find them all.
Use the four included screw-head bolts to connect the aluminum receiver onto the bottom of the seat piece. Make sure to get them extra tight, as these are not self-locking bolts.
Slide the elbow tongue into the receiver on the bottom of the seat piece, then bolt the top piece onto the back piece, using the two shorter screw-head bolts and the plastic receiver included in the kit.
Clip all the wheels into the legs. This may require an extensive amount of pressure, as the washers must pop over the plastic socket bracers. You will know that the wheels are secured when they click in to place.
Place the plastic spindle cover over the neck of the chair. It should slide easily down in to place.
Slide the neck into the base legs of the chair. Again, press hard and make sure that the piece is very secure.
Twist the top of the chair onto the neck piece until it is secure. Make sure not to cross-thread the piece when placing it on the neck.
Give yourself a nice open space to work in, so you wont lose parts or bump into other objects.
Always be careful of pinch points when working with chairs.