To remove the leaves from the stem, slide your fingers down the stem while holding the top, which will pull off the leaves as you go.
Fresh marjoram leaves are SO small that they usually do not need to be chopped.
Notes
Fresh marjoram leaves are SO small that they usually do not need to be chopped. For recipes that are cooked, you can sub in dried marjoram for fresh. Use 1/3 of the amount of dried. Don't use dried marjoram in dishes like salads where fresh is needed; sub in oregano instead.