In one sentence, describe what the following article is about:

Begin by opening the rim or cantilever brake using the lever (if applicable). If the bike has disc brakes, remove the retaining or cotter pin or the clips or springs that hold the pads in place. Pull the pads out with needle-nose pliers and set them aside.  To remove the front wheel, turn the bike over so it’s sitting on the seat and handlebars, then flip the quick-release lever over to the “open” position. Then, simply lift the front wheel off of the bike.  To remove the back wheel, crouch behind the bike. Hold the frame with your non-dominant hand and use your dominant hand to pull the derailer backward. Then lift the bike frame up and off of the rear wheel with your non-dominant hand and unhook the chain with your dominant hand. Let the air out of the old tire and use a tire lever to separate the tire from the wheel. Pull off both the tire and the inner tube. Reverse the process to install the tire and inner tube on the wheel that came with the conversion kit. Simply reverse the process you used to remove the wheel in order to reinstall it. Be sure to adjust the chain so it fits properly if you’re replacing the back wheel. If the bike has rim or cantilever brakes, simply close them over the new wheel using the lever. If the bike has disc brakes, put the pads back in place and secure them using the clips, springs, or cotter or retaining pin.  Adjust the brakes as needed, either by aligning the calipers (for mechanical brakes) or pumping the brake lever (for hydraulic brakes).

Summary:
Remove the wheel you need to replace. Transfer the tire and inner tube from the old wheel to the new wheel. Put the wheel with the electric hub on your bike and connect the brake components.