I know this is an older thread, but I just put my VT4 in a DSS bungee mount and thought I'd file this infobit away in the searchable Scubaboard archives for posterity.
Removing the VT4 (or similar computers) from the stock boot/wristband is pretty easy when you follow these steps:
1. Soak the computer with the original boot and wristband in warm (like a shower or bath, not scalding hot) water for a few minutes to make the plastic/rubber more pliable.
2. Take the computer out of its warm water bath and using your thumbs, push the edge of the boot that partially covers the rim of the computer up and over the rim to free the computer from the boot. This requires some dexterity and hand strength. I carefully used a plastic bicycle tire lever (like
Amazon.com: Tire Lever) to make this much easier.
3. On the VT4 and probably other computers, the strap ends are attached directly to the computer, not the boot. The strap is secured with watch-style spring bars. You can try using an improvised tool to press down on the shoulder of these bars, which are just barely visible between between the strap and the lugs that capture it on each side. But a watch spring bar tool (like
Amazon.com: 6" Spring Bar Tool) makes this task a breeze. Or, take the computer to the kiosk at your local mall that changes watch batteries and bands; they'll probably do it for free.
4. Installing the now bare computer module in the DSS mount is pretty straightforward. Soaking the mount in warm water and using the bicycle tire lever (very carefully) can make the job go a lot easier and quicker.
Hope this helps...good luck!