[sluggo]

Can you tell me how to replace the line vent filter? We have a 2000 29’ Open

I am a numb nuts when it comes to most of this stuff, but this was pretty easy.  It should be plug and play, that is, if you reorder exactly what you have.  I don't know where yours located, mine is right on top of my holding tank.  There are only 2 fittings.  The one that goes to your vent line, you should be able to just unscrew, so far so good.
Now the other end should go into your holding tank.  Mine has a little elbow that the vent screws into.  The vent may also be in a bracket.  So hold the elbow, but don't break it, and turn the vent tube out (righty tighty, lefty lossey), and it should come right out.  One year I had to put a vice grips on the elbow, but again just snug enough you don't want to break the elbow.

This year I found out that little elbow actually pops right out of the tank!  So if you can pop it out, it is a real easy job, just unscrew the filter from the elbow!!  Now reverse the process.  Screw the fliter into the elbow, pop the elbow back into the tank, put the filter in the bracket and replace the vent hose!  Done!!  Easy.  Let us know!!