Help with Tender proposal and Bid

I have been asked to bid on a tender for print work. I currently already work with this client and have done for many years but now they have decide to go out on a tender platform. We are a small company and this is very new to us but we will be up against much larger companies. I need help with the delta sourcing platform but more importantly the tender proposal that need to accompany the bid. We also run a design company so it is really just what would be written within the tender and how to make us sound fit for the job. We will plan to subcontract out most of the work where others will do in-house. As I have mentioned we currently do the work for half of whats in the tender so I need to push that across.
I have a full document I can show but this is part of what I have been asked to produce