Help me roots out control

Okay I got one plant it's candy Kush auto flower it's about week an half year old female. But the roots I notice started growing out of the drain holes in the potting container it is 2 gal pot the root coming out is two holes one is 5 inches long with a lot roots branching off the other root is 4 inches branching starting to beginning idk what to do I just filled up bigger pot with coco and placed the plant in the 2 gallon potting container on top the other pot I filled with coco but now when It comes time Im gonna need flush it and I can see this being pain In my ass. The medium for the candy Kush is 100% coco coir. Idk how or if I should transplant since it is auto flower and I wont be able to get entire roots system out undamaged it will Stunt growth to point auto flower will be waste time

Don't worry about the roots growing out of the pots holes this is normal and a good sign. Secondly never ever ever flush coco unless you are a couple of weeks away from cutting and you want your plant to become deficient. If you are worried about salt build up use and enzyme with your nutrient regiment and you'll be fine. If your plant is suffering from a Nitrogen burn or a mineral lock out you would
"leach" with a quarter strength nutrient mix. This way you don't go from having a toxicity problem to a deficiency.

Roots coming out the bottom is fine. Mine do that too. Eventually they will die off from light and they will quit doing that.