Raw vegetables are high in fiber and the best / easiest way is with a juicer. Otherwise, you could put vegetables in your blender or food processor. However since water content varies from vegetable to vegetable, you may have to add water or juice or broth to the blender if the vegetable is too thick.
Remember to scrub vegetables prior to juicing. It would be your choice whether to peel or not peel a vegetable prior to juicing or blending.
Not all juiced vegetables taste that good because vegetable juices are not as flavorful or sweet as fruit juices. Vegetables that taste well blended are celery, carrot, green pepper, tomato. Consider adding some fruit (banana or citrus juice) to vegetables when juicing. You may want to check with the manual that came with your juicer, blender or food processor for vegetable juice recipes.
When juicing, do not strain the fiber from the vegetables or fruits.