How can I get my inside cat outdoors?

[holaitsjosh]

I have a siamese cat and he's dying to go outside he loves window sills and always tries to run outside when i open the door. i've let him play in the grass but he's never been out on his own before. I want to get my cat some outdoor exercise by walking him or having him hang out on a chain in my backyard. What should I do?

I can't let the cat live outside because we have a bobcat near my house that killed my old cat