Unless you have some idea of what the password is, brute forcing the wallet will be near impossible.
That's not entirely true, notably for Electrum (and MultiBit Classic, and maybe one or two others with equally low key stretching).
I ran some
quick-and-dirty numbers based on
btcrecover's speed (which
isn't really a brute-forcer, I'm certain a real brute-forcer would be a few times faster).
Assuming only lowercase letters, passwords of length nine are quite feasible for an individual to brute-force.
Add in digits, and then it drops to about eight characters long.
Add in uppercase letters, then it's seven characters. Still not too bad.
Take a character off, and it goes from feasible to downright cheap ($10 and around 24 hours or less on a single monster AWS EC2 instance).
In short, brute-forcing weaker (yet not trivial) passwords
is possible, and none of this takes into account how a real brute-forcer would work, e.g. going off of good dictionaries w/good mutation rules.
Regardless, to OP: unless you're willing to try to find the password yourself (e.g. with btcrecover mentioned above), Dave has a good reputation and may be able to help (for a fee that is).
