Hold UP! Deep Sand Bed.... IF you dig in there DEEP (Meaning 4"+) you're going to release gasses and such that are trapped deep down. Some of these are very dangerous to your tank. I would do it something like this (I think)...
1) I would work on the "replacement" for the DSP... whatever you're hoping will take the place of it go ahead and get it started like in a bucket or something.. let the bacteria start to colonize it
2) When it IS ready... take the FUGE "Offline" completely from your system and remove/clean as a whole. This way you're not releasing any sulfurous gases into your tank
Hope this helps... now I've never DONE this so I'd wait for someone with detailed experience before attempting. Just take it slow