Now thats great that you should ask because I just got through replacing mine.
I have a 1997 36' Dolphin M.H. with a 454 fortect engine.
To open up the area where the fillter is located is just where you said it was you may have to get under the fender and if you look up to the top of the box you will see three metal pup ups, once you un snap those the back of the box will open up and you will have accest to the fillter.
Now I don't know if it a paper fillter or a metal one.
I have a Banks system on my M.H. so which ever one you have you will be able to replace it.
If its a Banks you will need to buy a K & E RECHARGER KIT.
because you can always use it all you have to do is clean it and the directions in the E & K package will exsplain it to you.
Just a thought.