sd70feb

hi everyone.......i have a 98 RS...CE light came on other day, and yesterday my speedometer started acting up.staying at 0 while driving or bouncing around....went to AutoZone to get codes pulled.....P0500...P1507...P1540. guy said its prob the vehicle speed sensor. saw a pic of it (kinda like an o2 sensor) i have no idea WHERE this would be or how difficult it would be to change it out....also the car stalled a couple times at stops....but not always...not sure if its related, but on my way to work today,no stalling.....car seems to run fine,just hate the CE light and usually get stuff fixed as soon as i can. ANY help very much appriciated. THANK YOU VERY MUCH.......