Following a comment on this product, I'm not too stressed the clamps, but apparently it would like very well with moderate tightening. For a little help against penetrating oil is not too much, to retract this 'sacred' pipe but without really struggled I put in about ten minutes.
If you remove an old pipe that has a tendency to stick, clean out the gas caps, it will save you many troubles. Do not forget also to put the clamps on the pipe before attacking you 'lembauchage' pipe :)