I want to be the friend again...?

this takes me 4 yrs back.. before then i was i was a boarding student.. i had this really good friend of mine. but after being friends for almost 5 yrs when we were in hostel now i became a day student.. keeping in touch with him was difficult.. we used to share our moments whenever we had time .. but slowly we started losing contact ..i started felling like he has turned into some other kind of person.. after some time we used to p each other as if like we had never known each other ... time ped and today after 4 yrs i feel that he thinks that it was me who ended our friendship .. now we r in a college and coincidentally we both are in the same cl.. we have difficulty talking to each other.. but now i m sure that he thinks that it was me who ended our friendship and that too intentionally .. i dont know how should i approach him .. he has somewhat changed from the kind of person i had known years back.. i want to be friends with him again ..