There are plenty of options available. Parking is available right in front of the museum, immediately across the street, and a parking lot is behind the museum, on the other side of the cistern.
There is also parking available in Hutchinson Square by the shops around the corner and the Summerville Parking Garage located in Short Central off of W 2nd Street.
This convenient location should make it hassle free, when planning an outing to the museum.