  We showed in a previous publication that there are six independent
dimension-seven operators violating both lepton and baryon numbers ($L=-B=1$)
and twelve ones violating lepton but preserving baryon number ($L=2,~B=0$) in
standard model effective field theory, and we calculated one-loop
renormalization for the former six operators. In this work we continue our
efforts on renormalization of the operators. It turns out this could become
subtle because the operators are connected by nontrivial relations when fermion
flavors are counted. This kind of relations does not appear in lower
dimensional operators. We show how we can extract anomalous dimension matrix
for a flavor-specified basis of operators from counterterms computed for the
above flavor-blind operators without introducing singular inverse Yukawa
coupling matrices. As a phenomenological application, we investigate
renormalization group effects on nuclear neutrinoless double $\beta$ decay. We
also discuss very briefly its analog in the meson sector,
$K^\pm\to\pi^\mp\mu^\pm\mu^\pm$, and indicate potential difficulties to compute
its decay width.
