In the first two years after planting, lightly prune rambler roses after flowering.
During these initial formative years, simply train stems onto adequate support framework and reduce sideshoots by two-thirds or to two to four buds from the main stem. As always, start by removing all dead, damaged and diseased wood so that you know what you have to work with.
Make sure you cut just above a healthy, outward facing bud with sharp secatures.
Whenever you are pruning roses it is a good idea to wear protecive gloves as the thorns can cut and scrape you easily.