From a standing position (first image) take a step forward with your unoperated leg as shown in the second and third images.
You may wish to hold on to a chair or worksurface to help you balance.

Allow both knees to bend together so that you come to a squatting position. Try to keep your feet flat on the floor.
To make this exercise more challenging you can bend more through your legs to get lower and closer to the floor.
Repeat 10 times.
Then repeat for the opposite side putting your operated leg forward (fourth image).