how can i reject him ?

I use to like this guy. I am not really sure that i am totally over him. He have a gf and he loves her. I used to talk to him every day for hours but not i can stay days not talking to him. I deleted his cell phone and the min he text, i respond to him right away. i mean i can stay days not talking to him but when he calls or text, i can't help but reply. How can i be strong and not reply? I think i am kinda over him now.i want to be just friends but the problem is he knows that i like him.plus he is flirt a lot. so should i talk to him when he text or call or ignore him and tell him to stay away from me ? plus he left his shirt over at my house and i want him to take it. so what should i do ? please no mean comment. i am trying to move on. i like to keep him as a friend.