removing brake pipes from 86 300e
 

is there any easy way of removing brake pipes that have been on my merc for its 20 year life?! i have tried my hardest but they are so rusted on i have duck oiled and wirebrushed them down but still have no luck , i need them off in one piece to take them to be measured for new ones... any suggestions?
regards, steve
merc 300 e 1986