You don't give a lot of info, but here's what happened with me (I should keep this text on my desktop for copypasta):
I knew myself well enough that I didn't "try to quit". For me, that is a recipe for insta-fail. I just kept my cigarettes farther away than my PV, and tried to vape more and smoke less. The first couple of weeks, I went from 3 packs per day to 1.5 - 2 packs, not quite every other cig replaced by vaping. Over the next couple of months, I obsessed over e-cigs, spent ......ed amounts of time here on the forum, and learned a LOT of tricks and nuances. I learned about direct-inhaling, dripping, 36 mg. juice, TV Butter Rum, and high-voltage big-battery mods. I bought lots of crap I didn't need, and that didn't work for me. I spent a lot of time being ...... off at e-cigs. I smoked any time I really, really wanted one. I got down to about 6 cigarettes per day. Then about 4. Then 2 or 3. Then one day, I realized I hadn't had a smoke in a couple of weeks, and I didn't want one. I had tricked my stupid brain into quitting when it wasn't paying attention. My last smoke was a day or two after Christmas of '09. Easy.
A couple of months ago, I tried to take a drag off of my wife's Marlboro Light 100, just to see. It tasted like burning garbage, and it was so foul I couldn't even fill my mouth with that crap. I blew it out without inhaling. I realized that I wasn't an ex-smoker, jonesing for a smoke all the time and one temper-tantrum away from smoking again. It's like I'm a "non-" smoker. I don't jones, I don't even notice when people are smoking around me, unless I smell that crap. My wife smokes, I don't even care.
Easy. Don't even try to quit smoking, just try to start vaping.