1. I'd like to find the missing word and I have the other 11.
2. I have 8 words in the correct order and 4 words out of order.
from the btcrecover library you need to run seedrecover.py
Here is link to the docs for that specific file
https://btcrecover.readthedocs.io/en/latest/Seedrecover_Quick_Start_Guide/
Here is the link to the file on github:
https://github.com/gurnec/btcrecover/blob/master/seedrecover.py
preferably should know the address of the funds, if not you can use a generated list of addresses used.
Be prepared to install python and some other required libraries
Good luck!
/KX