You have a few choices.
1. the instrumental version on the Gravity demos... but that one is totally different, and it's in the key of C.
2. the instrumental version on the MCIS electric Pumpkinland demos. But I'll be honest with you... I haven't listened to these demos in a while, so I don't really remember what this one is like.
3. it's probably available on some Karaoke disc somewhere. I don't know.
4. have someone do a cover of it for you.
The bottom line is, you're not going to find the exact album version minus the vocals. But one of these choices might work for you. What's the project you're working on?