I dont know if there is an official guide per se for things like that, but what I always personally give to customers is this. We run something like this on existing server -> clish -c "show configuration" > /var/log/current_config.txt (you run this from expert and you can output it into any dir and give whatever file name, just keep txt extension).
Then, you get the file using winscp (make sure /bin/bash shell is enabled) , and it will have all the current config of the appliance, which you can copy over the new one, just make sure not to copy anything that might be different. (copy in clish mode)
I never had an issue doing it that way.
Hope that helps.
Andy
P.S. Now, IF this was say management server and you wanted to copy all the policies/objects over (import them I shall say), then you would follow below process.
https://support.checkpoint.com/results/sk/sk135172