GTA Vice City: How to install without d3d8.dll?

I can't use the Reshade's d3d8.dll because several mods rely on their own d3d8.dll — overwriting would prevent the game from even launching. Installing as a DX9 title (and deleting the d3d9.dll) doesn't work. Is it possible to edit my DLL file?

maybe naming it d3d8x.dll would work?

Otherwise in some games you can use a custom dll name by putting the command line "-proxy name.dll" in the shortcut

Not possible. d3d8to9 is required since ReShade only supports D3D9+, so you need some wrapper that converts D3D8 to D3D9.