Replacement of bypass fuel lines...

My last injector is a little damp, as is the bypass hose and end "cap". As a preventive measure I'd like to replace all of the bypass hose from the filter to the first cylinder and then on back to the last and the end cap.
Must I use MB line? I've used 3/8" fuel injection line before but that was with a clamp and these appear to be held on with just friction.
Any tips for removing the old line and installing the new?
Do I have to bleed anything when I am done?