Ultrafast control of spin dynamics is necessary for next-generation spintronic devices operating beyond conventional speed limits, but the key challenge remains to achieve selective manipulation of magnetic exchange interactions. While above-bandgap photoexcitation transiently modifies effective exchange interactions, it generally does so without mode- or pathway-selectivity, offering little to no control over which specific exchange interactions are altered. Coherent phonon excitation enables targeted modification of interatomic distances, bond angles, and orbital overlap, thereby selectively renormalizing individual exchange pathways. Here, we investigate the coherent infrared-active phonon-driven renormalization of exchange interactions and spin dispersions in the cubic fluoroperovskite KNiF3 using a Wannier projection-based Green’s function methodology, resolving both the orbital- and mode-resolved contributions to the exchange interactions. We show that different phonon modes perturb distinct atomic sites and bond angles and distances, leading to mode-dependent renormalization of exchange pathways. The mode-dependent renormalization is further accompanied by the selective lifting of degenerate exchange interactions, thereby enabling control over individual magnetic pathways. The resulting magnon renormalization quantitatively reproduces the experimentally observed two-magnon energy modulation in KNiF3. We further determine the renormalization of the phonon energy due to renormalized exchange interactions via a coupled spin-phonon Hamiltonian, finding quantitative agreement with the anomalous phonon shifts observed in spectroscopy experiments. These results establish a comprehensive microscopic picture that links coherent phonon excitation to orbital-resolved exchange interactions and spin waves renormalization.