Spool Motor Mount Inserts

Never done this before and I can't seem to find the answer anywhere. I have new spool type inserts for my 73 Swinger /6. Do I just chisel out the old rubber from the old insert and pound the new ones in? Since the new inserts are surrounded in metal, do I bend the metal tabs back from the old one, slide out the entire middle section, put the new ones in and try to bend the outside metal of the insert? Pulling my hair out here!!:banghead: