If you are considering changing your tire yourself, some day when you have nothing to do, make it a point to actually change the tire to see what tools you will need and what is involved and determine if you actually have the strength, stamina and dexterity involved. You may decide that it is not for you. At the very least, you will know what is involved, which tools and accessories you need and have at least one practice run under your belt.
Consider the following:
Vehicle jack-I carry a thick board to provide support for the jack, absolutely necessary if you are on sand or loose dirt. Look at your owner's manual to see where to position the jack. if you have a scissors jack, make sure you have all the parts and handle extensions. Also, put grease on the screw that actually moves the scissors up and down. It will make using it much easier. Some vehicles have a bottle jack that works by hydraulic fluid. I also carry a tarp so I can put it on the ground when I position the jack and work on the wheel.
Tire chocks-Make sure you chock your tire. I usually put it on the opposite tire on the other end (If changing driver's rear, I chock the passenger front.) Two chocks are better than one.
Breaker bar and socket.-Purchase a 24" or 30" breaker bar with the appropriate socket in 1/2" size and determine ahead of time if you need an extension on the socket to reach the lug. Most lugs are torqued at over 100 pounds. A hand ratchet won't do it.
Lugs-Some lugs have a metal, chrome cover over the actual lug nut. What happens over time is that rust develops between the lug and the cover and it swells the cover. When you go to put the socket on it doesn't fit. If you have these type of lugs, replace them with solid, one piece lugs.
Anti-seize lubricant-I use anti-seize lubricant on the threads of the studs. This will minimize rust from forming. Technically, it does change the torque value when you tighten the lug nut. Probably go down 10 pounds or so, but in all my years of doing this, I have never had a problem with a lug nut, and the lugs come off easy the next time. If you are planning on changing your own tire and you have never had your lug nuts off, take them off one at a time and apply anti-seize to the stud. Then put the lug back on and torque to the recommended value.
Taking off your spare-Hopefully, you have checked the air in your spare. My Roadtrek takes 80 lbs rear and 65 lbs front. I put 80 pounds in my spare, but if I use it in the front, I take out 15 pounds. Carry an air gauge. My Roadtrek has the continental kit spare. The circular cover that covers the spare has a padlock-Make sure you have the key. The tire is held on to the frame with one nut (check the size-mine is different from the lug nut size). Make sure you have a socket)
Lifting the tire to hub-RV wheels and tires are heavy. Before I lift the wheel I visually line up the holes with the studs, then I usually roll the tire on a block so I don't have to lift it so much. An even better technique if to use a block of wood and a lever (a breaker bar works if you can balance it in the middle) to lift the wheel up to the height of the studs, then you can push it forward. (Imagine a see/saw setup-wheel on one side and your foot on the other to lever it up)
Tire tools-air gauge, portable air compressor and tire plug kit. Make sure you know your tire pressures. They are usually in the manual or on a label near the driver's door sill. A tire plug kit can be useful if you have a nail in the tread, not the sidewall. While this will not be a permanent repair, it may allow you to drive to a location where the tire can be fixed. You will also need an air compressor to fill the tire to see if the plug worked. If it does hold air, check it after 15 minutes or so to see if it is still at pressure. Obviously, don't drive at excessive speeds.
Safety items-Gloves, red warning triangle, reflective vest and light source. Make sure that other motorists are aware that you are stopped. Put on your flashers, position the triangle about 100 feet behind the vehicle, wear a reflective vest and have a flashlight or area light near you and the tire.
Location-If you have a flat and decide to change it yourself, use common sense and be safe. Pick a level place as far off the highway as possible. You may have to drive on a flat tire for a while before you can find a safe spot. If you are on a busy highway and concerned about your passengers, have them leave the vehicle and wait off to the side out of harms way. Above all, use common sense.
In summary, there is a lot more involved in changing tire beside a spare, a lug wrench and a spare. Most of the other tools and procedures should have been done ahead of time and practiced in your driveway on a nice, sunny day where you have all the time in the world and you are not in danger. Plan ahead; you will be glad you did and everyone will be impressed if you do have to change the tire in the middle of nowhere on a dark, rainy night on a muddy dirt road!