This is a fabulous exercise for building leg strength, and anyone that has a wall can do it! You might want to have a chair close by also, just in case you need the support.
Start by leaning your back against a wall, with feet shoulder width apart and about a femur length away from the wall (Just my cheeky way of saying that when you squat down, you want your knees to be stacked over your ankles).
Now press your low back into the wall, and slide down the wall until you are squatting! Just go as far as is comfortable – remember that you have to get back up again! Hold the squat position as long as you can, up to a minute or two, and then slowly rise back up, supporting your back on the wall.
If you didn’t feel that you are either in need of further instruction, or you are amazing!