This may not fully answer your question, but the process seems to be wireless and may rely on facilities whether planet-based or with ships like the Resurrection Hub and data-stream.
For resurrection to occur, the dying Cylon must be close to a
resurrection ship or hub, otherwise his or her consciousness risks
being permanently lost. The transmission method of a Cylon's
consciousness has not been explained, but a form of wireless is
probable. Resurrection points identified include the Cylon homeworld,
the central Resurrection Hub, Resurrection Ships, and planet-based
facilities. A rebirthing facility may have existed on occupied
Caprica. Within each resurrection point is at least one rebirthing
tank, where a duplicate body is immersed in a thick opaque substance
to await download (Downloaded).
In addition some of the pre-fall ers of the 12 Colonies' technology is featured in the prequel TV series Caprica. In that series viewers learn through the accomplishments of Zoe Greystone, Daniel Greystone, Lacey Rand, and Sister Clarance Willow that there is a link between a virtual reality with an ability to create a virtual avatar, whose information can also be downloaded into a robot body and can sustain said information transfer via MCP Chip.
But it should be noted that despite these accomplishments, that the final-five (No Exit, Final-Five Comic series, & comments from EPs about Caprica season 2) still made a deal with the Robot Cylons and possibly Zoe A, that resulted in the end of the first cylon war and the creation of the 8 new models, 7 of which are featured in Battlestar Galactica