Here’s a proposed implementation of NeverarGreat’s SKB explosion. He has isolated and recreated sound effects, and I’ve segued between this and the film’s soundtrack while adding music from the CD. His work was in stereo, so it has been duplicated into all channels save for the LFE track, leveled by ear against the relative balance of music and sound effects in the film’s soundtrack. When transitioning back to the film at the end, we first crossfade into an upmixed stereo version, then back into 5.1 in order to provide as smooth a transition as possible.
I do not have a 5.1 setup on which to monitor this, but listen to it track by track to compare it to the film itself in the hopes of getting it close to right. Please let me know if you hear any glaring problems.
https://mega.nz/#!HN4RhZ7R!zfF2L7uNt3dZckTgEc5Y5sMmTpwotz1Ofz54fdwv0dM