When the florist delivers roses to your home, the stems are typically thorn free. This is because the florist first strips the prickly thorns from each flower's stem before making the arrangement. There are tools on the market designed specifically for removing thorns. These rose strippers come in varying designs, typically used in the same way, by running the tool down the length of the stem. If you are bringing in roses from your garden, and want to remove the thorns, it is possible to do the task with a knife, if you don't have a rose stripper.
Hold the blade above the thorn, gently touching the stem and the top of the thorn.
Scrape the blade downward, along the stem and going under the thorn, to remove the thorn.
Move to the next thorn and repeat.