Deleting Files inside of A backup

Hi guys I have used Acronis in the past.

I am having trouble with turning an increment into the full backup. I have an image of a drive that is too large so I mount it in r/w mode and delete everything I don't want. But now there is the original and an increment. I don't know how to make the increment into the main and be able to delete the original!!!

I found one post here where the guy said to open the increment in the vault and run export command, but I don't know where the vault is or what the export command is!!!!!!

I need help fast! Thanks in advance!