I did mine about a year and a half ago and as far as I can remember I just forced it over the metal part. Did not use any glue. Mine came from Jamco Suspension. My problem was I couldn't decide which way to orient the pattern on the pad.
In retrospect Daniel, I may have heated it up in boiling water and used some sort of lubricant like soap.
Mark
1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia