I have never replaced the fresh/recirc. actuator on mine. However, in order to gain access, you need to pull the glove box. The box is held in by a plastic insert "rivet" with 2 parts. Pry up the insert and once removed, the outer ring lifts out.
If you just want to verify it's operation, in the upper back of the glove box is an oblong flexible plug. When you pry this out, you can see the flap open and close for fresh/recirc. air. (A handy little port for occasional air freshener also
).
Intermittents may be in the dash climate controller unit. This is easily repaired by touching up solder connections at the edges of where the circuit boards meet. (If you are not comfortable with circuit work, bribe a friend who is.
)