Migrate from Portal 6 to Portal 7

Hello Guys

Im asking you for your help.

I have a portal with version 6 and WAS 6.40 and SP19 , and my boss is asking me to migrate to version 7 of the portal and is asking me to give him how much time would I take to make this upgrade. Currently in my portal I have a j2ee development developed with Netweaver Developer Studio, also I have a development in Visual Composer version 6 which is published to the portal and is accesed via a bapi function with a user in R/3 and also in Netweaver developer studio I have a PAR development with jsp's used in an External Facing Portal. My questions are:

What are the steps to migrate the portal from version 6 to 7 without affecting these developments ?

Is there a manual to migrate portal from version 6 to 7 and where can I find it?

How much time would it take to updgrade the portal from version 6 to 7 ?

Is the Visual Composer 6 compatible with portal version 7 ?

If not what are the steps to upgrade Visual composer to the next version compatible with portal version 7 ?

Or is there a manual to updgrade the Visual composer ?

Thanks a lot for your answers

Rewarding point will be given

Luis