Practice, practice, practice.

If you want to get good at something and do it confidently & efficiently, you have to practice and develop a technique.

2 tasks that every rider is faced with and should be practiced consistently until they can be done competently:

1. Getting the wheels off & back on your bike with it oriented right side up. Practice doing it in the stand AND out of the stand on the ground. Surprisingly easy once you have the technique down.
2. Getting the tires off & changing the tube... Deflate the tire, remove it, remove the tube, then put it all back together & inflate. Rinse & repeat. Repetition is key here. Soon you will be doing it bare-handed.

Neither of these activities are difficult or complicated, the main obstacle for most people is only in their heads, IMHO.