From Houston I45: 

Take I45 North until you reach the exit for 2920 (Tomball/Spring Exit).  Turn left on 2920.  Once you reach the intersection of 2920 and 2978 follow the directions on the map below.

From Houston 249: 

Take 249 Northwest until you reach the intersection of Main Street in Tomball (2920) and 249.  Turn rignt on Main Street (2920).  Once you reach the intersection of 2920 and 2978 follow the directions on the map below.

From Conroe I45: 

Take I45 South until you reach the exit for 1488 (Magnolia Exit).  Turn right on 1488.  Once you reach the intersection of 1488 and 2978, turn left and follow the directions on the map below.