One Piece ABS Headliners ??

i used one from year one. nice fit and it was already covered black. it was like 230 shipped during one of their sales.

FYI, WHEN YOU GO TO INSTALL, DO IT WITH A HELPER!!!!!!!!!!!!!

Is this more to help hold it in place or because its a difficult install??? ive never done one before done carpet, seat covers, etc..never a headliner though...in other words would someone like my 11 year old son or wife be a ok helper...meaning they wound t have to do much but help not much mechanically??

and another question do I just need the headliner or so I need sail panels also?? Im seeing/getting mixed responses if I just need the 1 piece ABS headliner or the 1 piece ABS headliner+ sail panels...???