Special Internet Categories: Physics; Engineering Quantum Physics; Applied Mathematics. The emphasis in this monograph is on non-trivial path integral variable change on previously obtained path integral solutions for difficult stochastic and functional equations by keeping the main objective to arrive at... another path integral which the author expects to be in a 'final' suitable form of become predictive. Note that path-integrals are mathematical objects specially taylored to the work of our modern 'slavers': Computer machines.