use a sharp flat scraper of some type to rub off any remaining contact cement,then you can use some 60 or 80 grit sandpaper to remove the rest. As you sand the c.c. will clog up the sandpaper and remove it from the rail, it doesnt have to be spotless just smooth. Wipe them down with a wet rag to remove any loose debris and your ready to install the new cushions.
