You use WinDbg and do kernel debugging. The newer WinDbgX UI is quite nice lately. However, there's no replacement for live debugging on the same machine the way that SoftICE did it.

As I already mentioned in other comment, there was Syser debugger, but seems to be lost now.

https://qpdownload.com/syser-debugger/ (I am not sure how much is this link legitimate, so please be careful)

https://github.com/marakew/syser

IDK.

I had a problem because a company snuck their encryption scheme into their device driver. No problem with softice, today/now, it might be harder.