As you guys already know that Sony Ericsson has released the Gingerbread 2.3 OS for Xperia X10 Android mobile but if you are already on custom ROM then you can’t update via PC companion application, in that case you have to manually install the Gingerbread update. Download the Gingerbread 2.3 software from the links given below and follow the instructions.
Xperia X10 Gingerbread 2.3 Download
Multiupload link - Kernel and baseband from stock SE 2.3
Multiupload link - Recovery Image download
How to install Gingerbread update manually
Follow this thread on XDA forums as it is and you will be go through it just fine.