Use a big aerosol can of Cheeze Wiz.
As for the presumed question, order with right of return, put electrical tape over the rails of the saddle so you don't scratch it up when you clamp it, and wear clean bike shorts. Keep the saddle immaculate, and don't damage the original packaging. Then send it back to Amazon if it doesn't fit.
The problem with Amazon is that a lot of the stuff you buy there might have been returned for some reason. Usually you are ahead of the game if the previous owner hasn't substituted a rock in the original package.