  In the computation of Feynman integrals which evaluate to multiple
polylogarithms one encounters quite often square roots. To express the Feynman
integral in terms of multiple polylogarithms, one seeks a transformation of
variables, which rationalizes the square roots. In this paper, we give an
algorithm for rationalizing roots. The algorithm is applicable whenever the
algebraic hypersurface associated with the root has a point of multiplicity
$(d-1)$, where $d$ is the degree of the algebraic hypersurface. We show that
one can use the algorithm iteratively to rationalize multiple roots
simultaneously. Several examples from high energy physics are discussed.
