Hi,1990 5.0LX Mustang is the rubber hangers for after market catalytic converter the hardest part of job to get them free from hanger?Can the job, of taking off cats. and putting on off road h-pipe be done in ones backyard?Is there any special tools i need to get them off rubbers hangers or i just have to use harsh force ,dw-40 and a couple hours to get off?Any reason i may not be able to get them off the rubber hangers unless i take it into a muffer shop?The cats. are unbolted and hanging freely from muffers and headers.Thx fro info .if any.