If the makers of https://www.cryptokitties.co/ chose to port their dApp to EOS, can they? If yes, what are the point-by-point steps involved in the transition? What are the tools and tech required to make this adjustment?
Well, it is certainly possible. The contract would have to be rewritten into C++ because Solidity (Ethereum's native programming language) is not supported by the Eosio software.
Traditional software development tools could be used to port the code over to C++ and then it would be compiled into wasm (Web Assembly) in order to be executed by the Eosio blockchain. There is a native tool developed for use with eosio smart contracts, which is used to compile C++ code into wasm called eosiocpp.
More information regarding these tools can be found on the wiki! EOSIO Wiki - Programs & Tools
At the moment you would have to port solidity code (ETH) to C++ (EOS).
In the future EOS will support the Ethereum virtual machine so it could be possible to use existing solidity codebases with minimal changes.
Ethereum Virtual Machine (EVM) This virtual machine has been used for most existing smart contracts and could be adapted to work within an EOS.IO blockchain. It is conceivable that EVM contracts could be run within their own sandbox inside an EOS.IO blockchain and that with some adaptation EVM contracts could communicate with other EOS.IO blockchain applications.
Dan Larimer has confirmed the EVM is no longer a planned feature, you will need to port your code to C++.