Cubase 32 to 64 , end VST reinstall ?

Hello everyone, I ask one thing you will have already been asked, but I do not know where to find it. I installed Cubase 7.5 A 32-bit to Windows 7 64. If I reinstall Cubase 7.5 to 64, I must also reinstall all VST or just that there is a dll 64 and Cubase updating? There is a prpocedura explaining the procedure to go from 32 to 64? Thank you

same issues is why i did this video!
https://youtu.be/tof7AO2tqXY