If you’re using the UE4tools rig instead the only thing you have to do is parent your mesh to the rig using vertex groups, then edit the mesh to fit the rig using proportional editing in x-mirror mode.
If you’re using the UE4tools rig instead the only thing you have to do is parent your mesh to the rig using vertex groups, then edit the mesh to fit the rig using proportional editing in x-mirror mode.