I used up what I had and as it was done, I replaced it with vegan subs. When I ran out of milk, I bought almond milk. When we were finished with the fresh meat, I started making meals with alternative proteins like beans, seitan, quinoa, etc.
Sometimes it might take a while to build up a taste to the alternatives. My better half did not change with me, but eats vegan meals for dinner. He REALLY loves seitan, specially when it's browned in a pan and added to other dishes. He said he could eat it everyday because it tastes like and has the texture of chicken/pork. Tofu and tempeh is another story. Neither one of us have really found any recipes that changed out minds on those items. 
Now the canned meats/fish I donated to a local food bank. I figured that they could use the food, and I wanted to not have an excuse to drag on the transition.
Good luck!