Remove chipotles from can - I have found that sometimes there is not much adobo sauce in the can and you can just dump the contents on the cutting board
Slice the chipotles as thin as you can lengthwise, and then simply repeat crosswise until the pieces are as small as possible. You could use a blender, but slicing by hand gives a nice texture.
Place the diced chipotle mash into a glass container with a lid for sealing, such as a washed pickle jar or other reused condiment jar. Add the vinegar and stir. Use your judgment as to how thick to make the mixture. I like a little bit of runniness to use on sandwiches in place of traditional hot sauces.