I need help with a rootbound plant

I have about an 8 foot Lemon Haze that is rootbound to the pot. I need help getting it out of the pot without hurting or killing it. Any ideas or any kind of help will be appreciated. If anymore details are needed just let me know.

What size pot? I would cut the sides off the pot and peel it off then slide the plant into its next home. If going into another pot move the pot if possible on a low table so you can just slide her in

I'm going from a 10 gallon to a 20 gallon pot.

So do you mean cut the bottom off and then cut the sides off to?

I would cut the sides in 2 or 3 spots and then pull it down and slide the bottom off carefully. Or you could get help and hold the plant upside down and have someone pull it off. Shake out the loose dirt on top first. Smart pots are hard to slide off might be easier to cut one of those. If it's plastic you can do the flipping it upside down method

You might consider placing the smaller pot directly inside the larger pot on a layer of whatever grow medium you use already on the bottom, that way any spillage or fuck ups with roots breaking etc. are kept to a minimum. After you've got the plant set you can "backfill" around it to the right level.

Cutting your pot sounds like the best idea. One thing to note is if your plant is truly root bound, it will not continue to get bigger even if you replant it. A way to fix this is you need to cut some of the root system. This will trigger the plant to try and fix and reestablish the roots that were destroyed. Then the new roots will grow into the new soil and continue growing.

Don't cut any of the roots in the top soil near the stalk, you don't want to ruin any of the feeder roots. Once you peel that pot off, just stab some scissors into the very bottom in a few places, and maybe from the side in a few places. Don't get crazy with it. I would say about 10 stabs total, only where you see thin roots. You will see your plant start growing again in the next few days. I've done this quite a few times