From the bridge you will stay on Highway 3 until you reach Highway 23, about 17 miles. 

( An option: To speed the trip up, just after you go under "E. C. Row Expy" get in the right lane and take eastbound 401.  Stay on 401 until you reach Exit  10, which will put you right onto the round-about.) 

About 7 miles out from the bridge you will enter a round-about.   You want the second exit, labled "Highway 3, Leamington".  If you miss this exit, just continue around the round-about for a second try!  On the return trip, you also want the second exit, "Highway 3, Windsor".

The second map below is an overview from Google Maps.  To view the map on the Google site, use this link:  Overview Map