in this tutorial i would be teaching you how to quickly and properly change your paints from your paint cup. 

materials:

-tissue paper/cloth

-old paint brush

-thinners

-airbrush cleaner/old container

remember when airbrushing your colors always start from the lightest to the darkest, it makes the cleaning process easier.

now start by emptying out any excess paint from your cup into its container.

next using some tissue/cloth wipe the inside of the cup thoroughly.

repeat the process above, but this time add a small amount of thinner on the tissue/cloth.

this should remove the majority of any leftover paints.

now to clean the inner parts of the brush, pour some thinner into the cup and using an old brush clean the lower par of the cup.

pour another round of thinner but this time, spray it on a sheet of paper. if it comes out clean, you are ready for your next color.

PS- this process will not fully clean your airbrush, there will always be hints of paint inside the system. another thorough cleaning will be required.