Change source system from A to B

Hello,

We have a lot of infosources which have a connection to datasources from source system A. Some of that infosources contain formulas. Now we have to change to source system B with the same datasources and even the same content. What´s the best way to change without losing or filling in again the formulas and is there a way to do it not seperately for each infosource but for all infosources together, so simultaneously?

Kind regards,

Jos