Identify the location of the pantry closet. The easiest option is to choose a section of the kitchen wall without any cabinets on it so you don't lose any storage or countertop space.
Decide on the type of doors you want to use on the pantry. A regular door is one option. For a wider access point, consider bi-fold doors that give you a larger opening. Determine the size of the doors before you begin cutting the hole in the wall, as you only want the opening slightly larger than the door and its frame so you don't have to repair a large section of wall.
Mark the door size on the wall. Add 3 inches to each side and to the top beyond the dimensions of the door and its frame. This allows for additional framing to support the door.
Remove the plaster and lathe or the drywall that covers this section of wall on either side of the opening. Use a saw or hammer to knock out the material. Inspect the area behind the wall to look for electrical lines or other utility lines you'll need to relocate to accommodate the door.
Cut off the studs in the area where you will place the door into the new pantry closet. You now have an open wall space to begin the construction of the pantry closet. Once the closet is built, you will frame the opening and install the door to complete the pantry.