You can revise the offer you have already submitted. To do so, you need to either
Click "View documents and submit bid" in the original bid request email
Click "View bid" in the confirmation email you have receive for your previous bid
Access the respective bid package through the Bid request section in Cosuno (it will be marked with the status Bid submitted)
In the Bid packages exposé, you can simply edit the submitted BoQ. Alternatively, you can also upload a new BoQ, but need to clear the BoQ by clicking the "Reset"-button.
You can then send the revised bid, as with the first submission, using the "Submit bid"-button
After submitting your new bid, the tendering company will receive a notification about the changes. However, please remember to contact the tendering company personally for specific changes.