Sales tax/vat on self used manufacturing machinery

Dear Members,

Here is my query: "We have a food processing manufacturing unit setup in punjab in year 2012. We have paid Sales tax on these new machines. Now, we want to sell these machines to a buyer outside Punjab who is interested in buying our plant machinery. How should be bill/invoice the machinery price? Will this include VAT amount and what should be VAT amount?
If its only CST(2%), do we need a C form for the same? Do we need to prepare any other documentation while selling these machines to buyer? Any specific document for transportation or state border clearance?

Thanks for helping us.

Regards,

VK