From DisneyParks blog:
The Disneyland Resort has made stroller rental easy. There are now four self-service stroller rental kiosks at the Stroller and Wheelchair rental booth in the Esplanade, located just to the right of the Disneyland entrance.
It's easy to use, just bring a credit card, go to a kiosk, select your language (English or Spanish) and rent up to five strollers for up to six days.
See you there.