It is very difficult to kill a rose bush as a result of bad pruning, according to About.com. Although pruning roses can be a daunting task, it is good for the plants.
There is no agreed upon way to prune roses, but there are some basic techniques that can help make a pruning session more successful. Use clean, sharp long handed loppers, and start pruning at the base of the rose bush. Make cuts at a 45 degree angle and remove dead or diseased branches, instructs About.com. Rose bushes should generally be pruned in the spring but this varies by plant type and planting zone.