hello,
All you need to do is
1) extract the hash from the wallet
https://github.com/openwall/john/blob/bleeding-jumbo/run/electrum2john.py
from the john the ripper bleeding-jumbo pack (install python3 first, works on pc,linux,mac)
https://github.com/openwall/john/blob/bleeding-jumbo
python3 electrum2john.py yourwalletfile.wallet > hash1.txt
slow hash (worse)
or
python3 electrum2john.py yourwalletfile.key > hash2.txt
quick hash (better)

2) prepare appropriate dictionarries based on the information about the password

3) gather some GPU power and run the attack against the password hash.

if you need more explanations just ask.