A FINE question.
 
There is NO need to remove any part of whatever you currently have installed.
 
Just install 64-bit Sonar right alongside of your current 32-bit installation.  BOTH are simply programs that live on the same computer at the same time.
 
Even if you crash the beejeebies out of 64-bit Sonar trying out 32-bit plugins with either BitBridge or JBridge, it will not affect any part of your 32-bit Sonar or any of the 32-bit plugins.
 
AND, things may well work fine for you.
 
I suggest installing 64-bit Sonar and trying things out with your 32-bit plugins, using the default BitBridge - and if there are issues with stability, then move to one of the three options I put forth in my earlier post.
 
64-bit Sonar will install to the Program Files folder, and your 32-bit Sonar is installed in the Program Files (x86) folder.
 
I have used both 32 and 64 bit versions of Sonar for years, at the same time.
 
Bob Bone
 

Personally, the bridging part of the 32-bit from 64-bit is that on my machine, I lose some CPU resources for the actual bridging, and this is a 4/8 Core/Thread iCore7 CPU. Normally, in 32-Bit Sonar, I can mix 40-50 tracks, each with up to 3-4 plug-ins (if necessary, including Console emulation) and not flinch. Using 64-Bit Sonar with bit-bridging I can only mix about 20 tracks before drop-outs become a serious issue. That's something I have found that made me keep 32-Bit Sonar installed. 

Make a system image first so you can roll back if it goes wrong

jBridge can also be used to run 64-bit plug-ins in 32-bit Sonar, besides running 32-bit plug-ins in 64-bit Sonar like Bitbridge (and can also bridge between 32-bit plug-ins and 32-bit Sonar.)
 
Vienna Enemble Pro also offers such functionality, both on the same system or on a remote system, albeit at substantially higher cost (but with substantially more features) than jBridge.
 
That said, there are plenty of buggy plug-ins out there (both 32-bit and 64-bit) so... ymmv