You will need two (free) pieces of software:

vst3shell - https://www.xlutop.com/buzz/zip/vst3shell_v1.3.1.zip
shell2vst - http://www.xlutop.com/buzz/zip/shell2vst.zip

That's sufficient to create 64-bit VST2 plug-ins from 64-bit VST3 plug-ins. To transform these into 32-bit you will also need something like J-Bridge.

Create a folder to be the home for your new VST2 plug-ins - it doesn't seem to matter much where you put it, but it seems best not to use an existing VST plug-ins folder.

Extract the contents of vst3shell to this directory, followed by the contents of shell2vst (which has 64-bit and 32-bit versions).

Drag vst3shell.x64.dll and vsti3shell.x64.dll (for any VSTi's) onto shell2vst64.exe. All being well, that should create a subdirectory called (slightly confusingly) "VST3", containing 64-bit VST2 dlls for all of your 64-bit VST3 plug-ins (all of them ~5kb).

If you have 32-bit VST3 plug-ins, then dragging vst3shell.dll onto shell2vst.exe should do something similar, though I've not tried it.

You might be able to move the new plug-ins into SAW's VST folder, but I felt it safer to use "ini" files to point to them where they were created.

I've used this to get IzoTope Ozone 11 (64-bit, VST3 only) working in 32-bit SAW (with additional help from J-Bridge).