Valve spring removal ???

Dad and I are trying to put the new valve springs in(Comp) on the 273 and they come with the 2nd inner spring. Install procedure is to remove these for cam break-in and then re-install after break in. Well this is gonna be a pain in the arse...the valve spring compressor that dad bought from Canadian tire is a piece of junk and wont fit down with the positive style valve seals. Compressor broke once already. He went to a rental shop and rented a compressor, but it is the type where the head has to be removed. Any ideas??? We dont really want to have to remove intake and heads after cam break in:violent1: One trick that badsport mentioned is to use soft rope and drop it down each spark plug hole and turn engine over by hand so the valves dont drop down in, but the compressor is a piece of junk...Can anyone help??

Thanks
4spdragtop and ragtops pop