Yes, you can call Vanguard and they will help you move your husband's IRA to them. They will walk you through the entire process and will deal with Merrill Lynch on your behalf.
You can change the investments from the goofy ones to VTI or whatever you like either before or after the transfer, whichever is easiest and makes the most sense to you.
I will mention also that if Merrill Lynch invested your funds differently than what you asked for and you did not give them explicit permission to choose investments for you, then you can demand they make you whole. They should do this by exchanging the goofy investments for the ones you would have made at the time retroactive to when you did the rollover and made the original request. In other words, if back on that date you wanted to buy 1,000 shares of a Vanguard Target Fund that was selling for $50 at the time, then they should take the goofy investments out of your account and put in 1,000 shares of that Vanguard Target Fund even if that fund is now trading at $75. They also should reimburse you for any dividends you would have received but did not.
If they balk at making you whole, then you can explain that you're happy to involve the SIPC, the CFPB, your State Attorney General, and the Better Business Bureau.
That all being said, I just reread your post and noticed that you didn't check the account for six months, so that was a mistake on your part and so that may limit your ability to be made whole.