Anonymous wrote:assisted pull up machine or use those portable pull up bars you hang in the door way and use a chair to assist you.
Yes, start with the pull-ups bars that expand in the doorway. Start with the bar at shoulder height, hold the bar and walk forward about 2 steps, this will make you lean back a little, hang from your arms with your feet on the floor, do some pull-ups where you are not pulling the full weight of your body. Each day, keep increasing the reps that you do until you get comfortable with a fair amount (say 25 or so reps) at that height. Lower the bar 6" or so and take an extra step forward, you should be more inclined before and your arms will be supporting more of your body weight. Daily either increase the reps or increase the incline until you have the bar about waist height and you are essentially lifting most of your upper body with your feet/heels on the floor. Move the bar back to shoulder height and now step backwards 2 steps and bend your knees until you are hanging by your arms with your toes on the floor. Do pull-ups giving a little more support from your feet/ankles if needed. Keep making adjustments, slowly bearing more and more of your weight on your arms.
There is really no way to do this without slowly increasing the muscles in your arms and training those muscles. You can get expensive equipment to do it or just learn to use your body weight and start with what you can do and slowly increase the amount of your weight you bear. It will take months.