Replacing V21 fuel lines

[Blue_Runner]

So, this isn't my pic, but it is a very helpful pic posted by Destroyer (thanks D)when he replaced his V21 deck. You can see the fuel line running from the pickup at the front of the tank. There are cutouts in the bulkheads routing to the rear of the boat. If you look closely, you see the fuel line is secured to the boards across the fuel tank as well as the stringer in the rear. I took a mirror and a flashlight in the 8" inspection hatch and am able to see this same pathway in my V21. The thing is I won't be able to secure the new fuel line as I am not tearing up my perfectly solid deck. Additionally I do not think I will be able to get the old fuel line out, since it is attached in places I cannot reach very easily (maybe I can?). If I can't get it out I was thinking of plugging/clamping off the ends and just rolling with it. Any thoughts? WWYD (what would you do?)

[smokeonthewater]

Leave the old line in place and zip tie the new one to it... No need to plug the old one... Just blow any gas out of it.
Then go fishing

[bgreene]

I've cleaned the ends, then duct taped and even greased the duct tape section if needed to squeeze through tight spaces........pulls the old out till new........no problemo

[Blue_Runner]

10 - 4 not too worried about getting the old one out. Like the zip tie idea! Thanks Kevin.

[spareparts]

if the old one acts like it may pull thru, I use a Yamaha fuel line coupling(plastic union) and clamp the new line to it using Oteiker clamps(low profile, you can find them at lowes in the plumbing department), use the old hose to pull the new one thru.

Oetiker clamps are what they use on high pressure fuel lines, more than enough on regular fuel lines(USCG app.). Make sure to use A1 line as your replacement

[Blue_Runner]

Fuel lines replaced. I took a heavy piece of cable, duct taped a straightened wire coat hanger to the end of it and was able to fish it through underneath the floor on the very first try. Old lilnes would not budge - the line from tank to h2o separator nor the line from separator to primer. Used a mason jar and blew the fuel out of the lines as suggested. Worked like a champ. Thanks to all for suggestions. Will replace fill and vent hoses at some point but this was priority.