I paint with roundup using a small brush to coat all the leaves. Spraying can get on other plants unintentionally if nearby. Then they should die in a week (or repaint) and you can pull them out with the roots. This tool is a godsend. It might be time to resand/seal between the pavers.

If you don't want to use herbicide, other alternatives are boiling water or some people use diluted cleaning vinegar.