96 Nissan Altima 2.4 with leaking intake gasket?

[fritcr]

My daughter has a 96 Altima and it has been really vibrating at an idle. I have done a bunch of searches and I had noticed a vacuum sound under the hood at the intake side of the engine. I have looked and looked and could not find where it was coming from. I had sprayed carb cleaner all over and nothing.
Finally yesterday I was out of carb cleaner so I decided to spray the crap out of everything with brake cleaner. If I spray brake cleaner between the intake and the throttle plate and sort of UP...(this is hard to do) then the idle changes A LOT...in fact it will almost die. Would this be the intake gasket? Most of what I read it said the idle would go UP? But with the brake clean instead of carb cleaner is that why it trys to die?
Any help would be greatly appreciated. I think it is the intake gasket. If so...is there a write up or any advice anywhere on changing this. I'm very handy and have lots of tool and access to a lift also. I just don't know how much has to come apart to get that sucker in there and replaced. Sorry for all of the questions but I need to get it fixed. No codes by the way but it idles rough and the whole car vibrates.
Rob