Actually, you only need four things to flash dsx. Z4Root, D2 Bootstrap, the pre-rooted two part GB from TBH, and the DSX rom. Install Z4, reboot, and install D2 bootstrap. Next open bootstrap and and choose bootstrap recovery, hit ok after it says success, then choose reboot recovery. This will put you into bootstrap recovery. From there flash both parts of the pre-rooted GB and do a data wipe, davlik wipe, and factory reset before leaving bootstrap. When it boots reinstall bootstrap. If you don't have a copy of the apk saved just activate and setup your gmail and you can download it again from the market. Enter bootstrap again and flash dsx and sit back and wait. It takes a while for the first boot to finish.
Make sure you have a fully charged battery and save the zips to your sd card. I have root explorer, but I did not install it until after dsx, I used the stock "files" app to verify I had the zips om my sd card. When you save them, just save them to the card, don't save them in a folder on the card or you won't be able to flash them.
If it crashes or fails, don't panic, you can always sbf back to froyo. If you don't know what that is, find out first. If you can't sbf and flashing goes wrong, you're screwed. I recommend the linux cd method, simple painless, and noob friendly.
Read the DarkSlideX thread over at MyDroidWorld, all the instructions are there.
My Droid Thrives on the DarkSlide!!
