How the installation/uninstallation of VSPackage is done

I am building a VS Package that dynamically adds Command Bars.  Currently it does it on Initialize() which is wrong because every time a UI loads, the Initialize() is called.

I am looking for a way to handle the install or uninstall so I can add or remove those command bars.

Currently I am deploying that package by copying the build into the Extensions folder. What is the better way ?

Somewhere on internet, I read that an Installer Package (Installshield or something) can fetch the DTE object and add the permanent command bars and Uninstaller-part can do the same for removal. How can an Installer talk to VS or Isolated Shell and fetch the DTE ?

If you have information on how VS Package projects are deployed to Isolated Shell and removed, please share.

Thanks

Fahad