How to update Joomla 2 + VirtueMart 2 to Joomla 3 + VirtueMart 3

[yellow83]

Hi, I haven't found one clear guide how to upgrade j2 + vm 2 to J3 + vm 3.
I tried to do that by updating joomla 2 to 3 but it did not work, after that whole page went blank and nothing worked anymore.
I want to know how this should be done and in which order should vm and joomla and other components be updated. I have also joomgallery in Joomla. Please help

[GJC Web Design]

vm2.6->vm3

sort out your VM templates and any VM3 ext u need

then J2.5->J3

can be easy - can be VERY difficult..  IMHO the J2.5->j3 is the more problematic