From the Manchester NH Airport:
When exiting the airport, take Route 3A North.
Take 101 West (Bedford/Nashua/Concord), and cross the Merrimack River.
Exit onto the Everett Turnpike South (Merrimack/Nashua). This is a toll road.
Take the Everett Turnpike to Exit 8 (Route 101A West - Amherst/Milford).
At the second set of lights, turn left.

From Concord:
I-93 South.
North of Manchester, take I-293 South.
Just south of Manchester, I-293 exits, but stay on the highway, which becomes the Everett Turnpike South. This is a toll road.
Exit at Exit 8 (Route 101A West - Amherst/Milford).
Follow the exit ramp. At the second set of lights, turn left.

From Boston:
I-93 North to I-495.
I-495 South to Route 3 North.
Route 3 North into New Hampshire, where the highway is called the Everett Turnpike.
Everett Turnpike to Exit 8 (Route 101A West - Amherst/Milford).
At the second set of lights, turn left.

From Portsmouth:
Route 101 West to Manchester, and cross the Merrimack River.
Exit onto the Everett Turnpike South (Merrimack/Nashua). This is a toll road.
Everett Turnpike South to Exit 8 (Route 101A West - Amherst/Milford).
At the second set of lights, turn left.