I must admit I tried to make it through my (nearly new) copy of "Plan 9 from Outer Space" ... I had it for awhile, like a year or two before I finally put it in ... I survived about 20 minutes ... someday, I WILL finish the movie ...
One of these days I'm gonna have to see "Ishtar" and "Shanghai Surprise" just to see how bad they really are ...
First, you must watch the Johnny Depp movie about Ed Wood called "Ed Wood" and that should arm you with enough info to watch the real "Plan 9 From Outer Space!"
I also suggest a voluminous amount of mood altering devices of your choosing...
weed is best, I suggest several joints pre and at least one per half-hour... look at it as an exercise in comedy instead of fear...
alcohol is always good and drunkenness will help everyone scream out the stupidity of the flick...
that is all I can help you with.