My question are were in the FAR can I find if there is a requirement to Mod the Master because of the signature change? Also what is my authority to do this? Thank You
If you want to modify the BPA to change the signature authority of the company, that is a purely an administrative change as it does not effect the substantive rights of the parties. See the definition of "Administrative change" at FAR 43.101.
To do this you will use Block 13 B of the SF 30 and no authority citation is required.