I cannot offer any solid advice on the installation other than maybe lightly tap them all around with a rubber mallet so you are not necessarilly using brute force.You could use a roll of plumbers putty to replace the old.Best of luck and i hope you can make it work
David
http://FirstGenFirebird.org/show/closeup.mv?CarID=571 If i don't get this car back on the road soon i'm gonna go postal! On a quest for FGF knowledge 1968 Pontiac Firebird Convertible 1969 Oldsmobile Cutlass "S" Convertible *Sold*