you put it ontop of something smaller if possible say you got a 10gal one put it on a small bucket, roll the pot down like your rolling it inside out. easiest to do when the medium is somewhat dry. if the rooms are intertwined with the fabric which it likely will just gently yank it off. most it will do is cause transplant shock. been growing in fabric pots for a few months now i don't run anything smaller then a 2gal though
some fabric pots have velcro on the sides you just untie that and pull it out easy. i had no issues with the roots growing into the bags tbh but i typically try to transplant before that happens mainly because i pot up at least 2 times.
if you put the pot ontop of something smaller it's really easy just to roll it down probably takes you like a minute or less. you can also plant the fabric pots into another pot and the plants will still grow. also i find with my fabric pots they tend to only get stuck at the bottom. when you water it basically compacts the soil/medium you use kinda has some space overtime all around the pots. basically what i read is that the roots squeeze in the medium around it not sure if that is true or not but it's basically no different then what happens in say a solo cup. water it and then you see a small gap between the cup and the soil regardless how much you pack it.