An orchid is still kind of a mystery plant.
People think it's rocket science to move the plant from one pot to another, which is not true.
There are many nurseries providing re-potting services but those people are also like you only with more confidence doing the same thing many times.
You might want to read this page and some other related info and you are good to go with re-potting your orchid plant You need to understand that repotting is not conjure practice to provide colorful pot or big space for plant.
Repotting if not done at correct time it might cause problem for the plant.
Plant likes the original place but if you feel like changing it, you should wait till the plant has sufficient strength to reestablish.
Golden rule is never repotting orchids when it's flowering.
You should repot when new roots appearances that generally happens after flower fade.
If your orchid type gives flower many times a year you should go by either nine to twelve months period or check the root size if new root size is around six inches you could consider the pot change.
Please remember in emergency you could ignore above option.
If you know the problem with rotting medium, massive dead roots or pests please change the pot immediately.
Please remember orchids don't like to be disturbed.
Every time you mess with the roots, even the most vigorous orchid needs time and energy to recuperate.
If a plant is disturbed after the growing season is over, it may take substantially longer period to reestablish itself.
Orchid repotting requires little bit preparation.
The new medium won't absorb water quickly so day before you change the bark soak your potting medium in water.
For sphagnum moss, clay pebbles or prelate the same thing should be followed.
Make sure you have sterilized your equipment and you have gloves ready.
Before putting the plant in the new bark make sure you soak it into the water for about thirty minute so that roots become more flexible and it can lose the old composite.
You can cut the dead roots from the plant and disinfect them by adding sulfur or cinnamon on it.
Once you have clean your plant, you can clean the pot and reuse it or if you think orchid has over grown the pot size you can consider replacing it with new one.
Remember, new potting material doesn't absorb water, so you have to add water frequently at least for a month.
Put orchids in more humid and less bright place for about a week and then you can switch back to your normal practices.
Orchid like us don't like to get disturbed.
So I don't recommend repotting just because you have time on your hand at the same time if roots are growing out of pot or dead because of pests it's essential