I've successfully done both DMA/33 & DMA/66/100 cables with no trouble. I used a razor blade to gently score the cable housing at the intervals I chose (8x10 or 10x8 for DMA/66/100 cables). Do not use the blade to go all the way through, or along the entire length of cable. Just use it to start a crack in the cable housing, then force it apart with your fingernails. Repeat until the entire cable is separated, & then tie them into a bundle. Personally I used electrical tape to produce a square bundle, which worked nicely. I also cut off the end connector since I only needed one, & the extra was simply cable clutter. Just cut them cleanly & seal them with fingernail polish & it works fine.
Cables are cheap, if you eff them up just buy another.
Viper GTS