How to adjust the photos taken by 5D2 without texture?

Your question is vague, but let me make some suggestions to see if you can use it.

First of all, it may be that the light contrast is too big, which leads to the lack of details in the dark. Now that you use 5D2, you can start to learn lighting skills. Buy an entry flash, and a proper fill light can show details in the dark. (Or it's a good idea to use a polarizer.)

In addition, you can use spot metering mode. After metering is locked, the details in dark light will be better, but this may lead to underexposure, so use it as appropriate.