Hi. The simplest way is to use the summary of your posterior as parameters for your new prior. For instance, you have a Gaussian posterior with mean = 5 and standard deviation = 2, then your new informed prior could be a Normal(5, 2). There are some caveats to that I guess, maybe it’s a bit too rudimentary. You can see some discussion on using informed priors here: Bayesian Analysis Reporting Guidelines | Nature Human Behaviour
I’m sure others may answer you with a more sophisticated approach than the one I mentioned above.