Bench seat fitting mods

[dub boy]

Guys I've got a 2006 jaguar rear seat to fit in bus ,money's run out and this was free ,struggling to get my head round fitting it .the bac pert is a doddle as lots to fix from but the base :? I am not sure it's fairly dense foam but looks like it drops into a mold in jag if you know what I mean. Has anyone come across any threads on fitting these as there's buses with them fitted