In year three begin renewal pruning of your rambler rose, by cutting back up to one-third of all the oldest growth right back to the base.
This rose puts on growth repeatedly from the base, and it is this growth that needs to thinned out to the base.
Also reduce sideshoots by two-thirds or to two to four buds from the main framework stem. This should be done each autumn.
Whenever you are pruning roses it is a good idea to wear protecive gloves as the thorns can cut and scrape you easily.