Post #5 , above. The front wheel may have a small lever that you release by hand and an opposing threaded nut that you back off a few turns by hand. The front brake will likely need to be released first. Squeeze the brake pads together by hand and use the cable slack by pulling the little 90-degree metal noodle thingie out from its corresponding slot. The brake will spring open, permitting the wheel to be removed.

Rear wheel will be a bit more complicated because of the chain. Lay the bike on its left side, or upside down on its handlebars and saddle. Shift the bike to the smallest rear cog location. Release the rear brake caliper similarly to how you did the front. Loosen the outer axle nuts using the 15mm wrency, turning counterclockwise. Slip the rear axle forward or downward while simultaneously pulling back on the rear derailleur body, thereby making an opening for the rear wheel to pass away from the frame. As slack develops, slip the chain off of the rear cog and remove the wheel.

Installing is exactly the opposite in each case. Check to see that the wheel spins freely and that it is centered in its corresponding frame. Good luck.