Rigging

Open up the file with the model in it. Set up a new project in maya and make sure to save it. Make sure that the tool bar at the top is set to animation.

Start by selecting the Joint tool on the animation tool bar and click at the top of the hip to make the joint. Then click the knee, then the ankle, ball of the foot and then the toes. Hit the enter key to complete the joints.

Next position the skeleton into the middle of the leg, copy and paste the skeleton and put that one in the other leg. Click on the shading tab and hit X-ray joints. This will allow you to see through the leg so you can view the skeleton at the same time.

Create a small base of a spine between the legs and slightly above the hips in the middle, you only need one joint. Select the leg and the spine by holding shift, then press "P" to connect them. Repeat the same process for the other leg.

Click on the hip joint, hold shift and click on the ankle. Select the IK handle tool and change it to a RP connector. This connects the knee to the foot, so when you move one the other will move as well.

Click on the ankle joint and hold shift, then select the ball joint of the same foot. Create another IK handle but this time make it a SC handle. Repeat the last two processes for the other leg.

Create a joint that is inline with the ankle joint on the floor. Connect it to where the toe is then too the ball then the ankle, this is basically reversing how you made the foot in the first place. This process is called reverse foot lock and makes the foot act more naturally.

Parent the ankle, ball and toe joints of the leg to their corresponding joints on the reverse foot lock.

Now you have to bind the skeleton to the model. Select the model hold shift and select the skeleton. Select the skin tab then go down to bind then select smooth bind.

Once this is done the mesh and skeleton will be merged. The next step is weight painting, select the model and double click on the weight painting tool on the tool bar. You can select the different joints by clicking on them in the side menu that appeared when you opened the weight paint tool. When selected the areas that are affected will show up white on the model. You can add, take away and smooth this to make the model move more realistically, you have to paint on the vertexes as painting on the faces will have no affect. This can sometimes take a long time depending on the detail of the model and how precise you want the movement to be.