"safely" is hard. The right way to manage this stuff is through the Device Manager.
- Do a run: [Win]-r
- Type "devmgmt.msc" in the run dialog and hit Enter
From there you should be able to see your sound card. There's a lot of stuff in there which could break your system badly, so be careful. Right click and disable, or right-click and try to "Update Driver Software"
None of this is ever really "safe", but most of the time it's okay. Be sure that you've got a second machine or a friend who can help you should you get stranded. Windows takes pains to try to protect you from clobbering yourself, but the one time you really need it to work and have no way out, it will fail.
(to reinstall, you can uninstall the device and re-detect it and/or launch the driver's install program.)