I'm getting an '89 CRX pretty soon, but it has one of those huge "H" vinyl decals on the back window. I need to know how to remove this because it really makes the car look ricey.

id say if the color matches the car leave it on and show your honda pride! if not a gasket scraper works wonders. you can get a good cheap on from sears, the style that i found works best(just removed about 30 stickers off one of my rides) is the one that has a clip on the end that holds a razor blade. it makes it easy to apply pressure and still be able to carefully control it as not to damage anything else or yourself.:D

anything that allows u to scrape a razor blade will work great, such as a hobby knife, gasket scraper like 82civicwagon said, or just buy a pack of razor blades without a tool, just be careful if u do that even the dull end of the blade tend to drive itself into your hand and it has that strange property where u dont feel it until after youve seen it, so by the time u see it youve done a lot of damage. ive removed a couple stickers that while i was removing them suppenly i notice a little stream of blood on the window... and in case u didnt know, DONT USE THE RAZOR ON PAINT! try bug and tar remover for that.

I find that heating up the sticker with a hair dryer also works when trying to peel it off ...

you could try to heat it up, then use a razor blade.
I just used a razor blade for removing stickers on my side windows.