I went vegan last October, after being veg for about 6 months. For me, the hardest part about going vegan was deciding to do it. The rest was totally do-able.
I think I did a few things right, though: I did give myself lots of time to transition, so I wouldn't feel overwhelmed by change; and wouldn't feel that I was "forbidding" myself any foods, even though I ate about 99% vegan even during my transition; and I didn't tell people I was vegan, just that I was trying to eat vegan, so there would be no pressure from people watching what I ate and judging. For example, I love sushi, and I continued to eat tempura at the sushi place right next to work, even though I was fairly sure their tempura batter had eggs in it. And it worked--one day about 3 months in, I went down to the sushi place and said, "Can you check if your tempura batter has eggs in it?" It did. No more tempura for me! Not from there anyway, since other places make tempura with no eggs--I just have to ask.
For me, once I decided it was something I wanted, and something I felt strongly about, and something I was committed to, implementing that decision was easy. I've learned what parts about bein vegan are more challenging (eating at restaurants, visiting family, potlucks) and how to overcome them (plan ahead/call ahead, bring vegan snacks and ask for a trip to the grocery store, and bring two things so I have enought to eat). Everything is do-able now.