Hey, I've read how to do this by installing a 4.5mm spacer first, then the cassette itself....seems straight forward. On harris cyclery it says "you will need to remove the bolts holding the cassette together" right after it mentions how to adapt a 7 speed cassette to the 8/9 speed hub.
Do you really need to take the casette apart to do this? I don't get this....
Basically I have an 8 speed on there now, but can get the same range with a 7 speed and use my indexing on my downtube shifters this way.