Try this routine for a really intense leg workout.
The routine is quite advanced but offers strength training and cardio training at the same time. Leg exercises are never easy, but they are a great way to learn how to push through your pain barrier and make big gains.
If the routine is too hard cut down the number of reps and use the video as a short term achievable goal. Try the routine twice a week (Monday - Friday) and build up the resistance until you can keep up with Mike.