The best and safest way for both you and your bow is to use a bow stringer. This is a length of cord with ends that slip over the tip of your bow allowing you to step on the cords middle and pull upward exterting equal pressure on both limbs as you slide the bow string into place. Saunders makes a really nice one. I am currently having one that I make tested that I may offer to others. Be safe and treat you equipment well and the world will be a better place for you.
Shoot straight, aim well,
and tell tall tales to
good friends.