Since it clearly does not work, how would you reform the impeachment process?

It clearly is impotent beyond measure. The Democrats could have Perry Mason detailing and proving Trump’s guilt beyond even a sliver of a doubt, while he himself is advocated for by a literal chimp, and Republicans would still vote to aquit him.
And I doubt it would be much different if the sides were reversed.

So, how would you try to fix it?
Or do you think it is beyond saving, and abolish it instead?