Agree with both posts above.
I would use btcrecover preferentially to try to do this. Rather than use the link BitMaxz has shared (which is the link to the long abandoned original software), use this link instead (which is for a constantly updated forked version which will run faster and has better documentation on how to set up and use it):
https://btcrecover.readthedocs.io/en/latest/I would explore other means of recovering your wallet first, as 4 missing words in a known position still leaves 17.5 trillion combinations to try. This is assuming that they
are in a known position. If you are missing 4 words from an unknown position, then this becomes exponentially harder and maybe impossible depending on what hardware you have available.
Do you know an address from the wallet in question (preferably the first one)? It will make the process somewhat easier if you do.
You'll also want to set up a token list with your 8 known words, but this will be pretty easy to do and I'm happy to guide you through it. Obviously don't share your other 8 words with anybody who offers to help.